A pergunta formulada no título foi dirigida à autora por várias pessoas de todos os tipos e afazeres. A presente nota é uma tentativa de resposta, a fim de satisfazê-las ao menos em parte. Uma resposta curta não poderia atender a mais do que uma fração da pergunta, pois, necessariamente, deve ser concisa. Este texto identifica a principal peculiaridade dos manguezais no fato de serem criados e mantidos por um pequeno número de plantas vasculares arraigadas no solo da faixa tropical entre marés. O manguezal é um ecossistema marginal com grande e variado número de interações com outros ecossistemas, próximos, adjacentes ou remotos no tempo e no espaço. Outra particularidade é que, diferentemente da maioria dos ecossistemas marginais, é um sistema altamente dinâmico, muito produtivo e com capacidade de imobilizar sais de metais pesados.

The title question of this short paper has been addressed to me countless times by persons from all walks of life. The paper is a concise answer to the question; it might go halfway towards satisfying the questioners, but not more than halfway. This paper identifies the uniqueness of mangrove ecosystems in that they are created and sustained by a small number of rooted vascular plants in the intertidal area of the tropics. In addition to being a marginal ecosystem, a mangrove is unique in that, as an ecosystem it has various interactions with other ecosystems, both adjoining and remote in space and time. Another unique feaure of mangroves is that, unlike most marginal ecosystems, they are highly productive and dynamic. Healthy mangrove ecosystems also have the peculiar ability to immobilize heavy metals.

Descreve-se uma nova espécie de hidromedusa, coletada em águas costeiras próximas a Santos, pertencente ao gênero Octocanna Haeckel 1879. Este gênero foi considerado obsoleto por KRAMP, mas o achado presente mostra que deve ser reestabelecido. A nova espécie chamada Otocanna haeckeli pertence à família Phialuciidae. Difere das outras duas espécies do mesmo gênero por ser menor, ter umbrela alta em forma de domo, 4 tentáculos, 8 bulbos e 8 vesículas marginais quando atinge a maturidade sexual. A validade do gênero Octocanna fica restabelecida para as Phialuciidae com 8 canais radiais, 8 gônadas, 4 ou mais tentáculos e nunca mais do que 4 lábios. O gênero Octophialucium Kramp 1955 é mantido como válido para Phialuciidae com 8 canais radiais, 8 gônadas e 8 lábios. Na mesma série de amostras foram coletados alguns espécimes de Octophialucium bigelowi Kramp 1955 que se assemelham à primeira vista a Octocanna haeckeli, mas têm 8 lábios, 8 tentáculos, bulbos rudimentares e um número maior de vesículas marginais quando sexualmente maduros. Ambas as espécies atingem a maturidade com aproximadamente o mesmo tamanho e foram coletadas na mesma massa d'água, em datas próximas do mesmo ano.

A new species of Hydromedusa belonging to the genus Octocanna Haeckel 1879, here revived, is described from the coastal waters off Santos. The new species belongs to the family Phialuciidae, it is named Octocanna haeckeli sp. n. and differs from the other two species of the genus in being smaller, in having a high dome shaped umbrella, four tentacles, eight bulbs and eight marginal vesicles at sexual maturity. The genus Octocanna is here revived for Phialuciidae with eight radial canals, eight gonads, four or more tentacles and never more than four lips. The genus Octophialucium Kramp 1955 is considered valid for Phialuciidae with eight radial canals, eight gonads and eight lips. In the same series of samples, some specimens of Octophialucium bigelowi Kramp 1955 were taken which are very similar to Octocanna haeckeli but have eight lips, eight tentacles, rudimentary bulbs and a larger number of marginal vesicles at sexual maturity, which is reached at approximately the same umbrella size. The two similar species were taken in the same water mass at approximately the same time of the same year.

A análise de 247 amostras quantitativas de plancton coletadas durante três anos em três estações fixas ao largo de Cananéia, Estado de São Paulo, até 17,2 milhas ao largo e a 28 m de profundidade, revelaram a presença de 28 espécies de medusas, 17 das quais foram estudadas detalhadamente. 1) As oito espécies seguintes podem ser consideradas bons indicadores da massa de água costeira: Podocoryne mínima, Bougainvillia ramosa, Stomotoca dinema, Laodicea minúscula, Obelia spp., Eucheilota ventricularis, E. duodecimalis, E. paradoxica. 2) As seis espécies seguintes são bons indicadores da massa de água da plataforma: Euphysora gracilis, Eucodonium brownei, Turritopsis nutricuia, Proboscidactyla ornata, Amphogona apsteini. 3) Uma espécie é bom indicador de massa de água tropical: Aglaura hemistoma, além disso ocorrem duas espécies ubiquistas. 4) A distribuição das espécies no espaço acompanha de perto a das massas de água. 5) No conjunto essas medusas são mais tolerantes em relação à temperatura do que à salinidade. Isso pode ser devido à procedência das amostras, todas de águas de pequena profundidade e portanto com uma fauna adaptada e sujeita a variações relativamente intensas de temperatura. 6) Não há duas espécies que tenham curvas semelhantes em relação à freqüência/temperatura ou frequência/salinidade, com os mesmos máximos ou com extremos comparáveis. Espécies com preferências semelhantes para salinidade, têm preferências diferentes para temperatura e vice-versa. 7) O plancton é um tipo de ecosistema juvenil, que todavia pode ser relativamente mais ou menos maduro. A massa de água costeira, submetida a mudanças contínuas é a que se mantém em estado mais juvenil de todas as estudadas no presente trabalho, enquanto a massa de água tropical (Corrente do Brasil) é a relativamente mais madura, por ser u'a massa de água velha com variações de menor amplitude e de período mais longo. A massa de água costeira é intermediária entre as duas. 8) Espécies ou fases do ciclo específico que ocupam um alto nível trófico num ecosistema jovem não podem alcançar um nível de independência do ambiente e de eficiência muito altos e portanto ou abandonam a vida planctónica ou não alcançam um nível de eficiência e estabilidade mais altos. 9) Há indícios de que certas espécies toleram concentrações de salinidade inferiores ao ótimo em temperatura baixa e vice-versa salinidade mais alta do que o ótimo favorece a sobrevivência em temperatura mais alta. Esse fato é comparado à relação temperatura/umidade do ar que foi demonstrada para certas espécies terrestres. 10) A tolerância de uma maior amplitude de variação, certos fatores ecológicos como temperatura, salinidade, etc, em condições experimentais por parte de animais planctónicos, pode ser explicada pela existência de competição inter e intraspecífica no ambiente natural, enquanto que no laboratório todos os fatores são mantidos no seu ótimo, afora aquele experimentado. Esse fato é relacionado também com o que tem sido chamado "character displacement" (deslocamento de caracteres). 11) As espécies de medusas da massa de água costeira apresentaram maior número de indivíduos, o que sugere maior produtividade dessa massa de água ou um mais alto nível de maturidade nesse ecosistema.

Os autores fizeram uma revisão do gênero Bougainvillia, incluindo todas as espécies descritas sob esse nome e todas aquelas realmente pertencentes a esse gênero, anteriormente descritas sob outros nomes. De cada espécie é dada uma lista de sinônimos a mais completa possível, assim como uma descrição detalhada. As espécies válidas são reunidas numa tabela sinótica com os dados que foi possível reunir para cada espécie. Estabelecida a sinonímia na base dos caracteres morfológicos, foi estudada a zoogeografia do gênero. Tudo indica ser B. ramosa a forma simples primitiva da qual derivaram as demais espécies. Desta forma, ou de outra próxima a ela, teria derivado um grupo de espécies de águas temperadas com certas características morfológicas comuns a todas, e, afora uma que é do Japão, habitantes do Atlântico ou mares adjacentes. Um segundo grupo de espécies teria evoluído em águas frias árticas ou boreais e antárticas, também com caracteres morfológicos em comum. Por fim, um terceiro grupo de espécies teria evoluído em águas tropicais tanto do Atlântico como do Pacífico, apresentando, igualmente, características morfológicas em comum. Considerando o número de espécies e sua distribuição, o gênero Bougainvilia aparece como um gênero inicialmente atlântico, havendo apenas duas espécies distribuídas exclusivamente no Pacífico ou Indo-Pacífico.

During a seven days trip to the oceanic island of Fernando de Noronha, plankton was hauled from depths varying between 50 m and the surface. All the nets used were open nets, one was 1 m wide at the mouth, the other 25 cm wide. Due to lack of suitable equipment only the surface temperature and salinity were taken. Five holoplanktonic species wore collected, being Aglaura hemistoma the most abundant (145 specimens) and present at almost every station. Next in frequency of specimens and number of stations are: Liriope tetraphylla (27 specimens), Rhopalonema velatum (25 specimens), Solmundella bitentaculata (2 specimens) and finally Geryonia proboscidalis (1 specimen). Most of the specimens were immature. Of the meroplanktonic species, the most abundant was Eutima mira (7 specimens), next Obelia (perhaps Obelia geniculata). 4 specimens), Phialidium sp. (the medusa of the hydroid Clytia. 1 specimen). a fragment of Clytia cylindrica (hydroid). Sarsia sp. (the medusa of the hydroid Syncoryne, 1 specimen) and a few hydroids of Syncoryne sp. Numerous fragments of thecate hydroids, some taken alive, some not, were also present in the samples. On the whole, the present collection is characterized firstly by a great majority of oceanic forms both in number of species and number of individuals and secondly by relative abundance of benthonic specimens in the plankton. The author believes that the first fact may be explained by the geographical position of the island, placed 175 miles away from the edge of the continental shelf or north-eartern Brazil. The second fact might be explained by the strong impact of the South Atlantic current on the insular shelf that may be strong enough to tear fragments from the benthonic hydroid colonies. Due to the impact upon the island's submerged portion, upwelling or strong turbulence might insue, responsible for the presence of benthonic animals in the plankton. Benthonic nematodes were also present.

Estuda-se neste trabalho a fauna de hidromedusas das águas brasileiras em sua sistemática e distribuição. 1 - Todas as espécies são descritas em detalhe porque a maioria é nova para esta parte do Atlântico. De várias dá-se uma sucinta revisão do gênero. Uma espécie é descrita como nova: Laodicea minúscula. Seus caracteres específicos são: tamanho diminuto dos espécimes sexualmente maduros; apenas quatro tentáculos bem desenvolvidos, perradiais: quatro bulbos interradiais; manubrium pequeno; oito córdilos, ocelos ausentes. A presença de Eucodonium brownei constitue achado zoogeogràficamente inesperado. Bougainvillia frondosa foi reencontrada agora pela primeira vez depois da descrição original. Corymorpha gracilis é mantida como espécie distinta de Corymorpha (Steenstrupia) nutans europea. 2 - As medusas aqui estudadas pertencem, tipicamente a uma fauna de águas quentes. Quatorze espécies têm reconhecida ou provável distribuição circuntropical ou são vastamente distribuídas. Sete são exclusivamente Atlânticas, sendo 3 destas exclusivas do Atlântico ocidental. Apenas duas são comuns ao Atlântico e Pacífico. A única espécie nova é de águas costeiras. 3 - Na massa de águas costeiras, cuja salinidade é inferior a 35‰, foi encontrado o maior número de espécies diferentes. Dez destas são exclusivas de águas costeiras. 4 - As águas da plataforma, com salinidade entre 35 e 36‰ caracterizam-se pela grande quantidade de espécimes, sendo indicadoras dessa massa de águas: Corymorpha gracilis, Proboscidactyla ornata e Turritopsis nutricula. 5 - As águas do norte, com salinidade acima de 36‰ caracterizam-se por uma associação de espécies holoplanctônicas, sendo indicadora: Geryonia proboscidalis, e havendo preponderância de Aglaura hemistoma sobre Liriope tetraphilla. As águas do norte tornam-se cada vez mais empobrescidas à medida que progridem para o sul. 6 - Há indícios seguros de que várias espécies realizam migrações diurnas verticais, entre outras: Proboscidactyla ornata, Turritopsis nutricula, Cunina octonaria. 7 - Todas as espécies oceânicas são holoplanctônicas, circuntropicais e representantes de gêneros monotípicos ou de pouquíssimas espécies. As espécies meroplanctônicas são costeiras ou de águas da plataforma, com distribuição geográfica mais restrita. A abundância relativa de Aglaura e Liriope parece ser inversamente proporcional. 8 - Faz-se, por fim, uma comparação com os resultados alcançados no estudo das medusas coletadas pela Great Barrier Reef Expedition.

Tendo sido encontrado na região de Fernando de Noronha abundante material morfológicamente intermediario entre Pterosagitta draco e P. besnardi, proveniente esta última da região da Ilha da Trindade, os caracteres anteriormente considerados como disjuntivos foram reestudados em material proveniente de ambas as zonas. As conclusões a que se chegou são: P. besnardi é sinonimo de P. draco. 2.º - P. draco é muito provavelmente uma espécie politípica. 3.º - Provavelmente existe um gradiante morfológico no Atlântico, representando o material da Trindade o extremo sul da área de dispersão da espécie.

In this paper are given distributional records of species already known to frequent brazilian waters. Full description and figures are given of speoies not hitherto known from this coast. Of the mentioned 2O speoies of hydroids, 5 are new for brazilian waters (Eudendrium carneun, E.capillare. Campanularia laevis, Amphisbet ia pulchella, Aglaura hemistoma); 3 are known only from the ooast south of Cabo Frio (Eudendrium carneun, Campanular ia laevis, Ob*lis commit sura 1 it. O.griffini, Thaumant ias raridentata, Orthopyxia crenata = O. lennoxent it, Geminella tubtilit, Amphisbetia pulchella); 7 are found both to the north and south of Cabo Frio (Pennaria fragil is, Clytia cylindrica = C.attenuate, Hebella scandens, Dynamena crisiodes f. typica, Sertularia marginata f. typica, Schisotricha billardi, Aglaophenia rigide); 4 species have a wide distribution (Eudendrium capillare, Obelia bicuspidata = Gonothyrea bicuspidata, Macrorhynchia philippina, Aglaura hemistoma) and finally of one species the known area of distribution was extended further south than Cabo Frio: Hebel la scandens. Cabo Frio has been tentatively considered as a natural zoogeographical frontier. The name Pennaria is used instead of Halocordyle, beoause the first described species certainly belonging to this genus was Sertolara pennara of Cavolini, later redescribed by Goldfuss in 1820 as Pennaria disticha. Stechow's opinion that considers oorreot the name Halocordyle is abandoned and the author now follows Bedot's view according to which the correct name for this genus is Pennaria. The speoies described for the Brazilian coast must therefore be called Pennaria fragilis (Van.). Eudendrium carneum was kept alive in sea-water aquaria. The by dran the have a well developed pseudohydrotheoa, they feed voraciously on small animals, mainly copepods and require thoroughly oxygenated water. They are rather difficult to raise in aquaria, and frequently the heads fall off or are resorbed. In these instances, the gonophores development proceeds at the expenses of the remainder portions of the coenosaro. The gonophores are produced around hydrants which become totally resorbed during their development, quiokly so in the male colonies, muoh more slowly in the female ones. Only one planula is produced in each female gonophore. The larvae emerge by rotating slowly using the orifice as fulcrum and so unscrewing themselves, so to speak, out of the gonangia. The pianolas locomotion is partly due to their oiliary covering and to a greater extent to gliding and active contraction and distension of their body. They are bright orange red and have a strong positive phototaxis. They become attached and from 60 to 66 hours after eclosion (water temperature from 23 to 84º C), the first polyp is completely formed. Eudendrium capillare was found in an aquarium and is here recorded for the first time for this coast. Campanularia laevis previously known only from cold sub antartic waters, was now found in the region of Cabo Frio at 67m depth. The hypothesis has been presented earlier of the existence of upwelling in this region (Vannucci 1951). A short description and figures are given of this species, which seems to be a cold water species. The gonothecae of Obelia bicuspidsta of these waters are here recorded for the first time. An extensive sinonimy of this species is presented, based principally on the work of Hummelinck. The finding of Orthopyxis billardi nom. nov., described by Billard as Eucopella crenata has made it possible to determine the sinonimy of Orthopyxis crenata and O.lennoxensis and clear the confusion until now existing for what concerns this species. Orthopyxis billard i has an interesting type of articulation by means of soft peridermic portions connecting successive hard segments of the peduncle. This articulation must confer to the peduncle a high flexibility associated with high resistance. Amphisbetia pulchella new for Brazil, was collected at Rio de Janeiro, a large, dead colony. Aglaura hemistoma, as was to be expected since it is a circumtrepical planctonic Trachynemid, was found to be abundant at 5-10m depth about 20º lat. S - 36º long. W, Jaseur Bank. Four species of Scyphoxoa are recorded, none of them is new. The first was described primarily by Fritz Muller from Sta.Catarina; it is the common Chiropsalmus quadrumanus, a voracious carnivore it is a very common species and is usually entangled in the fishermens nets, specially during summer. Chrysaora hysoscella was already known from Brazil, and was now collected in the low salinity waters of the region of Cananéia (southern part of the coast of the State of S.Paulo). Stomolophus meleagris and Lychnorhisa lucerna are two very common, even if not very abundant, species.

1) - Foram estabelecidas em S. Paulo algumas colónias de E. mediterranea proveniente das águas salobras da região de Cananéia afim de completar as observações realisadas in loco. 2) - São apresentadas tanto a descrição como a classificação, incluindo uma rápida comparação com quase todas as outras espécies desse gênero que foram até hoje descritas. 3) - Descreve-se o ciclo completo desde a desova até a postura da geração seguinte. Não foi feito o estudo embriológico detalhado. 4) - Foram anotados o habitat e a alimentação, e verificada a ausência de cnidocistos em animais não alimentados com hidrozoários. 5) - Foram estabelecidas as temperaturas letais e a duração das principais fases do desenvolvimento em temperaturas diferentes. 6) - Foi feita a comparação com o ciclo de E. pallida, otimamente descrito e figurado por Rasmussen (1944). 7) - Foi verificada in loco a ausência de migrações. 8) - Considera-se essa espécie, sem dúvida eurihalina, um ótimo material para o estudo das relações entre o meio interno e a pressão osmótica externa.

A rich colony of the cladohepatic nudibranchiate mollusk Embletonia mediterranea was studied from the lagoon region of Cananéia, from March to July (end of summer through winter). To the author's knowledge this species is here redescribed for the first time since its description by Costa (1866), fulfilling some omissions present in the original paper. A comparison is here made with 4 out of the remaining 8 species of the genus. All the species are closely allied, two of the species which were not compared for lack of the necessary bibliography, are probably only a variety of E. pallida which is known to the authors. These are: E. juscata and E. remigata. E. minuta, also not compared, may be a synonim of E. pulchra. The fourth uncompared species: E. pygmex is the only one totally unknown to the authors. The colony became well established in aquaria in S. Paulo where the animals reproduced freely. The whole individual cycle was observed from spawning of a generation to spawning of the following one. The egg masses are lump-shaped, they contain an average of 11 eggs; each full-size animal lays about 16 to 17 eggs in 24 hours. Spawning begins in animals about one third full length. The whole development, from spawning to hatching takes from 48 h to 60 h in temperatures from 20º C to 25º C. Few days after hatching the veligers settle to the bottom and after 24 h to 48 h the young ones abandon the nautiloid shell yet with no cerata neither rhinophores and with reduced cephalic expansions. A comparison is made with the development of E. pallida, described and wonderfully portrayed by Rasmussen (1944). This species is closely associated to Bougainvillia on which were always found numerous egg-masses and adults and on which the animals feed. On the athecate hydroid, are usually found several cauli of Obelia bidentata. Animals reared out of reach of living hydroids had cerata entirely devoid of cnidocysts. In spite of its natural association to the mentioned hydroids, the species is euryphagous since it thrives well in captivity feeding on detritus and perhaps diatoms, small ciliates and suctorians. There is no annual cycle, the species having been found active continuously from summer through the coldest months. No migrations have been recorded and the population seems to be stationary the year round. Finally it was pointed out that this species seems to be a suitable material to study the problems of the relation between the internal medium and the external osmotic pressure.

This paper presents the taxonomic results regarding the Chaetognatha collected during a voyage to the oceanic island of Trindade made in 1950. Collects were done at different stations around the island and in the waters above banks between the island and the continent. Seven different species were collected, 5 of which belong to the genus Sagitta: 8. bipunctata, 8. enflata, 8. friderici, 8. hexaptera, 8. serratodentata, one is recognized as a new species of the genus Pterosagitta: Pt. besnardi, and finally the last is Krohnitta subtilis. Descriptions and drawings are presented of the species, as well as records of what is known of their habits and of the environments which they select. The new species, Pterosagitta besnardi, the second known of this genus, is as a whole similar to its elder: Pt. draco; but differs from it in some essential points. Pt. besnardi is shorter, its caudal segment is proportionately shorter, it has a smaller number of teeth and hooks, the hook's sheath has no crest, it has intestinal diverticula, its receptacula are extremely large and have a clavate shape and, finally its vesiculae are short and oval. This work was done aiming at a better knowledge of the Chaetognathous fauna of the western south Atlantic and for this purpose more work is being prepared dealing with the coastal species. Random informations are being pieced together in the hope of gathering in the near future enough material to establish some useful indicator among the species of this group that might be efficiently used for practical purposes.

From the Jaseur Bank, off the Brazilian coast at 20º 30' S - 35º 50' W, were collected a few specimens of one of the less known species of the Heteropoda: Firoloida lesueuri (d'Orbigny). A detailed anatomical description follows aiming at the elucidation of some obscure points in the litterature on the subject and at showing the identity of most of the previously described "species" of the genus Firoloida. Special care was taken with the study of the nervous system of which most of the descriptions found were discordant. The author arrived at the conclusion that the pleural ganglia are either missing of fused to the cerebral ganglia, that the supraintestinal ganglion (left parietal ganglion) is present in the posterior region and is close to the subintestinal or right parietal ganglion, being both located near the rear end of the body. The innervations are described and discussed as well as the fusion of extensive tracts of the connectives. The present material is shown to be identical to F. kowalewskyi, well described by Vayssière and Tesch; F. desmaresti (Lesueur 1817) is shown to be undistinguishable from F. blainvilleana and F. gracilis. F. aculeata and F. gaimardi are here considered as "nomina nuda". F. liguriae Issel 1907 is admitted as separate species in spite of its insufficient description and, finally, F. vigilans (Troschel 1855), unsatisfactorily described from only one specimen is perhaps a valid species. A table is presented to show the slight differences between the 4 species which are undoubtedly very similar. F. desmaresti is found only in the Atlantic north of the line and a few points south and close to it as well as in dependent seas, while F. lesueuri is common to the south Atlantic, south Indie and south Pacific oceans, extending north only up to the Azores Islands. F. liguriae is from the south western Atlantic. ?F. vigilans would be an endemic species from Messina (Mediterranean).

This work was done with the aim of computing all the species of Hydrozoa (Siphonophora excluded) that have been collected on the Brazilian coast, or in the pelagial, near the coast (some of the "Meteor" Stations). Nutting's (1900, 1904, 1915) and Mayer's (1910) monographs were taken as starting points and later papers and the Zoological Record used to check posterior findings. As a whole, 116 different valid names, among species and forms, have been mentioned from the Brazilian coast, distributed among 60 genera. Of the 116 species, 82 are represented by hydropolyps, 30 by hydromedusae (11 of which belong to the Trachylina and therefore lack a polypoid generation) and finally, by 4 species of which are known both polypoid and medusoid generations. The subdivision of the coast has been made at random, on account of the scarcity of the findings, except for the best known district, that goes from the latitude of Vitoria (State of Espirito Santo, at about 20ºlat.S.) to the bay of Santos (State of São Paulo, about 24ºlat.S.). The latitude of Cabo Frio (23ºlat.S.) was considered as a possible natural barrier, and the results of the global counting of the distribution of the hydropolyps North and South of 23ºlat.S. is the following: 29 species are known only North of Cabo Frio, 26 only from the same latitude (see direction of the coast, along parallel 23ºS.) or further South and 28 species are known both North and South of the coast (of these, 5 species are "cosmopolitan"). Therefore it seems quite possible that Cabo Frio really is a barrier to the distribution of 55 species. 26 species are endemic to the Brazilian coast, of these, only 5 are found both North and South of the Cape, while-14 are found only North and 7 only South. No studies can be done, on the bathymetric distribution in relation to the latitude. These results must be considered as provisory since more extensive researches will probably alter these figures. However, I believe that they are significative as a mean index of the condition of the hydrozoan fauna of the Brazilian coast. A tentative working hypothesis is presented as to the possible factors that confer such a zoogeographic importance to the region of Cabo Frio, a fact that has been foreseen by Ekman (1935, p. 73). Geographic position, currents, latitude and nature of the sea bottom between the continent and the oceanic island of Trindade have been taken in consideration, and all of them seem to be possible eficient factors of separation. Furthermore, according to the data obtained by the "Meteor" Expedition in July 2, 1926, at station 164 (23º8'lat.S. - 42º5'long.W.) and station 165 (23º35'lat.S. - 40º52'long.W.) and by what is known by hearsay and local experience of the region (exact continued study is urgently needed), it seems possible that, off from the sharp curve that the coast has at Cabo Frio, there may be an irregularity of the general scheme of the current and local upwelling may be present that would explain the local low temperature, low salinity and high density of the superficial layers as well as the abundance of fishes; these factors might contribute towards the establishement of a zoogeographical barrier. Further work is needed and nothing more than an hypothesis can be presented for the moment.

In Anis paper are listed 19 different species of Hydrozca collected during a trip to the oceanic island of Trindade, located at lat. 20º 30' 00" S. and long. 29º 22' 00" W., 600 miles off the brazilian coast. During the trip hawls and dredges were done at different points of the island and of banks that exist between the coast and the island. Of the 19 listed species one is here considered new to science: Hebellopsis besnardi (p. 83), characterized by having thecae with a single curvature and a strongly everted margin. Its measures are intermediate between those os H. hartmeyeri and H. sinuosa, which are its closest allies. H. besnardi was found epizoic on D. quadridentata. Of the remainder 18, 14 were already known from the brazilian coast. Of these 14, 4 were previously known only from the coast south of Cabo Frio, and 10 are at present known only from the region north of Cabo Frio. Five species are found both north and south of this Cape. As a whole, 5 species are recorded now for the first time on the brazilian coast, of these are given a full description and figures. This paper has the purpose of increasing the faunistical knowledge of this region of the Atlantic Ocean as a first step towards the understanding of the zoogeographical relationships with the other oceans and the establishment of the zoogeographical regions of this coast.