SOUTH AMERICAN NEMATOGNATHI. 165 



ANALYSIS OF THE SPECIES OP PIMELODUS. 



. Head granulated, entirely naked above . 



b. Length of adipose dorsal 3i in the length or shorter; caudal rays not 

 produced, not much longer than head; maxillary barbels not extend- 

 ing much beyond tips of caudal, mostly much shorter, 

 c. Intermaxillary band of teeth present. 



d. Anal rays 11 to 13; adipose dorsal longer than base of anal. 

 e. Caudal obliquely rounded, the lower rays much the longer; 

 occipital crest as wide as long, its tip deeply forked, receiving 

 dorsal plate in its notch; anal narrowly rounded. eques 120. 

 ee. Caudal deeply forked. 

 /. Anal rounded. Intermaxillary band of teeth twice as wide 

 as the mandibulary band. Snout projecting. ornata 121. 

 //. Anal emarginate, some of the first rays extending beyond 

 the tips of the last. Intermaxillary band of teeth scarcely 

 broader than the mandibulary band. 



g. Teeth on pterygoids usually present; the vomerine patches 

 of teeth reduced to a minimum or absent. 

 h. Teeth on the vomer, none on the pterygoids; head rather 

 broad, flattish, grauulose; eye small, 7-9 in head. 



albicans 122. 

 hh. Minute patches of teeth on vomer or none; pterygoid 

 teeth usually present; eye large. 



i. Caudal with brown bars. pictus 123. 



a. Caudal without brown bars. clarias 124. 



gg. No teeth on vomer or pterygoids. 

 j. Lips thin, normal;body thickly covered with black spots. 

 Dorsal spine i longer than head; adipose dorsal longer 

 than head. Maxillary barbels reaching past anal, mental 

 barbels past middle of pectorals; postmental past base of 

 ventral. Eye 3 in snout, 6^ in head. Lower jaw in- 

 cluded; depth of intermaxillary band of teeth 4 in its 

 width. Opercle J longer than the diameter of the eye. 

 Pectoral plate elongate, subelliptical, its width 3^ in its 

 length. Caudal lobes pointed, the upper longer than 

 head. Adipose dorsal about 3^ in the length. Pectoral 

 spine about equal to the head in length. (Steindachner.) 



grosskopfii 125. 

 jj. Lips very thick; teeth on intermaxillaries in a very 

 short band. Head pointed, almost conical, granulated 

 to near posterior nostrils. Maxillary barbel extending to 

 near tip of caudal, sometimes shorter. Eye midway be- 

 tween posterior nasal opening and gill-opening, more 

 than 5 in head, less than two in interorbital. Mouth 

 very narrow. Dorsal spine serrate behind, as high as 



