of the Island of Trinidad^ W. I, 45 



Family. 



GONIODONTES, AgASSIZ. 



Subfainil/y. 

 Hypostomin^, Gill. 



Genus. 

 Hypostomus, Laoepede, Kner, 



Body oblong and moderate, sub-angular, covered by several 

 rows of high, imbricated plates, which are more or less pectinated 

 posteriorly. Abdomen covered with very small granulated 

 plates. 



Head large, broader than the body, depressed, with the ver- 

 tical aspect semi-oval, and with the eyes oblique, and visible 

 from above. Branchial apertures advanced far forwards, and 

 under the eyes. Interopercula with the margins simply pec- 

 tinated or dentated. 



Mouth moderate, with the labial veil semicircular and entire, 

 straight and narrow in front, with broad and rounded margin be- 

 hind, and with the whole of the inferior surface studded with 

 papillae ; opposite the angles of the mouth, a small tentacle 

 is often continued from each side of the veil. 



Teeth rather short, slender, curved, and with hooked apices. 



First dorsal subquadrate, placed over the bases of the ven- 

 trals, and rather higher than long. 



Anal small, composed of one simple and four or five soft 

 rays, placed a short distance behind tlie anus, and between the 

 first and second dorsals, or under the last rays of the former. • 



Caudal forked or lunate ; the lobes nearly equal, or the lower 

 slightly longer than the upper. 



Pectoral large, with the first ray a large and robust clavate 

 spine, beset with villiform teeth. 



Ventrals moderate, with the first ray simple, large, car- 

 tilaginous, and flexible, and with asperities similar to those 

 on the pectorals. 



