The observations made about the stomach of Trichogenes longipinnis (Britski & Ortega, 1983) showed a rounded organ which has in its dorsal side an accessory structure - a cul de sac - that comunicates with it. The distal part of this dorsal accessory presents characteristic of an organ that exercise respiratory functions: reduction in the thickness of the mucosa and arrangement of an intrincate continuous capilar net in close contact with the superficial cells of the epithelium. In this portion there are no glands in the lamina propria. The epithelium shows a superficial squamous cels; they are very slim, and sometimes, with the capillary endothelium form a single barrier between the organ lumen and the blood. Polyhedric cells are also present in this epithelium; they are located under the squamous cells, sheltered between capillaries and basal cells.

Trichogenes longipinnis (Britski & Ortega, 1983) is a leather fish restricted to the rivers on the shore in the southeast of Brazil. In this work, the oesophagous structure is being showed. The oesophagous appears itself short, dorsally inclinated toward pericardium and ventrally covered by liver lobe. By electron microscopy we can observe a mucosa layer formed by stratified squamous epithelium and lamina propria with stratum compactum. The epithelium is composed by three types of cells: superficial squamous cells; mucous cells, similar to the globet cells and polyhedric cells. The stratification of this epithelium provides a complete basal layer of proliferation polyhedric cells. The cells in the intermediate region of the epithelium are also polyhedric. These cells are just bellow the superficial squamous cells and packed among mucous cells.