53. PIMEL0DT7S. 125 



not extending on to the basal bone of the dorsal spine. Adipose fin 

 very long, its length being contained twice and three-fourths in the 

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

 than the length of the base of the latter. The maxillary barbels 

 extend to the end of the dorsal fin, the outer ones of the mandible 

 to beyond the root of the pectoral. 



The height of the body is contained seven times and a half in the 

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

 a half. The lower jaw is rather shorter than the upper ; the band 

 of intermaxillary teeth is about six times as broad as long. Inter- 

 orbital space concave, its width being equal to twice the diameter of 

 the eye. Dorsal fin with the spine very feeble, scarcely higher than 

 long. Pectoral fin short, rather more than half as long as the head ; 

 its spine scarcely exceeds the humeral spine in length. A minute 

 porus axillaris. Ventral fin very short, shorter than the pectoral. 

 Anal fin small, the length of its base being equal to that of the dorsal ; 

 its posterior rays do not extend to the end of the adipose fin if laid 

 backwards. Caudal fin cleft nearly to the base, short, the upper obe 

 being less rounded than the lower, the length of which is one-seventh 

 of the total. Blackish ; dorsal fin with a whitish band across its 

 middle. 



Guatemala. 



a. Seven and a half inches long. River of San Geronimo. From the 

 Collection of Messrs. Godman and Salvin. 



20. Pimelodus nicaraguensis. 

 D. 1/6. A. 13. P. 1/9. 



Head covered with thin skin above. The adipose fin is very long, 

 two-fifths of the total length (without caudal) ; it commences almost 

 immediately behind the dorsal, and terminates at a very short distance 

 from the caudal. The maxillary barbels extend to, or a little beyond, 

 the origin of the adipose fin, the outer ones of the mandible to the 

 root of the pectoral. 



The height of the body is one- seventh of the total length (without 

 caudal), the length of the head two-ninths ; the head is depressed, 

 rather narrow, its greatest width being two-thirds of its length ; the 

 diameter of the eye is a little less than one-half of the extent of the 

 snout, and two-thirds of the width of the interorbital space. The 

 least depth of the tail is contained twice and two-thirds in the length 

 of the head. The lower jaw is a little shorter than the upper ; the 

 band of intermaxillary teeth five times as broad as long. Dorsal fin 

 with the spine very feeble, a little higher than long. The length of 

 the pectoral is two-thirds of that of the head, the length of the spine 

 two-thirds of that of the fin. A minute porus mucosus in the axil. 

 Ventral fin scarcely shorter than the pectoral. The length of the 

 base of the anal is rather more than that of the dorsal ; its posterior 

 rays do not extend to the end of the adipose fin if laid backwards. 



