53. PiMELODxrc 127 



caudal), the length of the head rather more than one-fifth. The 

 lower jaw is the shorter ; the band of intermaxillary teeth is about 

 five times as broad as long. The eyes occupy nearly the middle of 

 the head, their diameter being two-thirds of the width of the inter- 

 orbital space. Dorsal fin with the spine very feeble, higher than 

 long. Pectoral spine half as long as the head ; a minute porus 

 axillaris. The posterior anal rays extend nearly to the vertical from 

 the end of the adipose fin if laid backwards. The free portion of the 

 tail is higher than long. Caudal fin forked, with both lobes rounded, 

 their length being contained six times and a half in the total. Uni- 

 form blackish. 

 Mexico. 



a. Five inches long. Purchased of M. Parzudaki. 



23. Pimelodus motaguensis. 

 D. 1/6. A. 12. P. 1/8. 



Head covered with soft skin above ; occipital process short. Adi- 

 pose fin long, its length being contained thrice and a fourth jn the 

 total (without caudal) ; its distance from the dorsal is a little less 

 than one-half of its own length. The maxillary barbels extend to 

 the end of the dorsal, the outer ones of the mandible to the root of 

 the pectoral. 



The height of the body below the dorsal equals the height of the 

 tail above the anal, and is contained six times and a fourth in the 

 total length (without caudal) , the length of the head five times and 

 a half; the greatest width of the head is three- fourths of its length. 

 The lower jaw is the shorter ; the band of intermaxillary teeth is 

 about five times as broad as long. Eye a little nearer to the ex- 

 tremity of the snout than to the gill-opening, its diameter being 

 two-thirds of the width of the inter orbital space. Dorsal fin with 

 the spine veiy feeble, higher than long. Pectoral spine striated, 

 strongly serrated along its inner margin, and entire along the outer 

 one ; a minute porus axillaris. The posterior anal rays do not ex- 

 tend to the vertical from the end of the adipose fin if laid backwards. 

 The free portion of the tail is as high as long. Caudal fin forked, 

 with the lower lobe rounded and with the upper slightly pointed ; 

 the upper is the longer, one-sixth of the total length. Upper and 

 lateral parts brownish, the lower whitish ; dorsal with a white band. 



Rio Motagua. 



a. Nine inches long. From Mr. Salvin's Collection. 



24. Pimelodus laticauda. 



Pimelodus laticaudus (Heck.), Kner, Sitzungsber. Wien. Acad. xxvi. 

 p. 420. 



D. 1/6. A.. 13. P. 1/8. 



Head covered with soft skin above ; occipital process short. Adi- 

 pose fin long, two-sevenths of the total length (without caudal) 



