THE CATFISHES OF VENEZUELA — SiCHULTZ 189 



206. Teeth not in form of a band behind premaxillary band of 

 teeth. 

 21a. Width of head equals length of head; no patches of 

 palatine teeth, but two patches of vomerine teeth; 

 dorsal rays I, 6 or I, 7; maxillary barbel reaching or 

 not reaching as far as adipose fin; width of mouth 

 IV^ in width of head. 



Steindachneria Eigenmann and Eigenmann 



216. Length of head longer than width of head, latter 1.5 to 



2.3 in its length; premaxillary band of teeth very 



wide, with a backward-projecting arm, laterally. 



22a. Palatine patch of teeth comma-shaped, confluent 



with vomerine patch; width of head 2.2 in its 



length; maxillary barbel not reaching past dorsal 



fin, width of mouth nearly equal to width of head, 



3.2 in length of head; adipose about equal length of 



anal fin base; back and sides of body with blackish 



bars; all fins with black spots; anal rays v, 9; 



pectoral I, 8; gill rakers about 3 + 9. (Fig. 3, 



a) Pseudoplatystoma Bleeker 



226. Palatine patches of teeth oval and separated from 

 vomerine patches. 

 23a. Vomerine patches of teeth widely separated; pre- 

 maxillary band of teeth with a concavity lacking 

 teeth at inner midline but almost enclosed 

 posteriorly by a toothed armlike projection to- 

 ward midline; maxillary barbels longer than 

 total length, ossified out as far as opposite dorsal 

 fin, thence flexible and bandlike, ending in a long 

 hairlike filament; total length of adipose fin 

 much longer than base of anal fin; width of head 

 lYio in its length; width of mouth across angles 

 iKo in width of head and 2yio in length of head; 

 gill rakers about 5+12. (Fig. 3, g.) 



Platysilurus Haseman 

 236. Vomerine patches of teeth confluent in midline; 

 premaxillary band of teeth wide without partially 

 enclosed edentulous space at inner side at midline; 

 maxillary barbel reaching a little past caudal fin 

 but not ossified or bandlike; width of head 1}^ in 

 length of head; width of mouth across angles V/i 

 in width of head and 2.2 in length of head; gill 

 rakers about 4 + 11 ; adipose fin much longer than 

 anal fin base. (Fig. 3, 6.) 



Duopalatinus Eigenmann and Eigenmann 

 16. Gill opening not extending far forward, gill membranes joined to isthmus or 

 in front of pectoral fin; dorsal raj^s I, 6; teeth villiform in a band on pre- 

 maxillaries and on dentaries; no teeth on vomer or palatines; margin of eye 

 not free; pelvics inserted far behind base of dorsal fin; pectoral ?pine pun- 

 gent, about I, 7; anal base long, of 16 to 40 branched rays; postcleithral 

 process a triangular, broad-based spiny projection. (AuchenipteridaeK 



533749—43 2 



