

SOUTH AMERICAN NEMATOGNATHI. 165 



ANALYSIS OF THE SPECIES OF PIMELODUS. 



. Head granulated, entirely naked above. 



6. Length of adipose dorsal 3| 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. 



ff. 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, granulose; 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. 



ii. 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 \ 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, 6J in head. Lower jaw in- 

 cluded; depth of intermaxillary band of teeth 4 in its 

 width. Opercle \ 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 



