GILBERT AND STAKKS — FISHES OF PANAMA BAY 27 



merely dusky in others. The vomerine patches vary somewhat in size and ishapu. A 

 very narrow groove may be detected, separating them in all of the specimens, and 

 they do not seem to be wholly confluent with the palatine patches even in adults. 

 The pterygoid bands may be wholly absent, or represented by a linear group of 

 small patches, or fully developed as an elliptical patch of large size. 

 Nine specimens were preserved. 



41. Netuma insculpta {.for dun ((• Gilbert). 



Hitherto known only from tiie ty|)e (an adult male) and two young co-types, 

 all from Panama. To these, the jiresent collection has added an adult female, 27 

 cm. long. 



The species is very close to iV. planicept<, but diflfers in its wider head, more 

 numerous and coarser granulations, wider occipital process, longer barbels, and 

 shorter higher adipose fin. The occipital process is less sharply keeled, and the 

 palatine teeth are in larger patches. In our specimen, the vomerine patches are 

 large, the apposed magrius rounded, meeting in the middle but not confluent; 

 evident furrows mark them off from the palatine patches. The latter are very 

 large, with straight jjarallel inner edges, as in N. platijpogon. 



In the following measurements the specimen varies somewhat from the type 

 description: 



Head 8| in length. Interocular width 2i in head; snout 2|; width of mouth 

 (external measurement) 2; maxillary barbel reaching to end of second fifth of the 

 length of the pectoral spine; outer mental barbel to little past gill-opening. Occip- 

 ital |)rocess a little wider at base than its length on the median line. Length of 

 predorsal plate on the median line one-third the length of one of its sides. The base 

 of the adipose fin is contained 2f times in the head, its height If in its length. The 

 ventrals overlap the rudimentary anal rays. The anal has 14 developed rays, 3 rudi- 

 ments. The posterior face of the pectorals is black, the other fitis dusky. The 

 maxillary barbel is silvery white, with a black upper margin. 



42. Netuma planiceps (Steindachner) . 



Of frequent occurrence. This proves to be an extremely variable species, the 

 variations not being dependent on age or sex, and not correlated. The occipital 

 process may be very much narrower than figured by Steindachner (1876 b, PI. 

 IV), more tapering posteriorly; or it may be broader than there represented and 

 more expanded at the base, so that the lateral margins are more concave and the 

 greatest width and length of the plate are about equal. There is usually a wide 

 shallow groove extending backward from the fontanel to within about a pujjil's diam- 

 eter of the occipital process. This is often obscured posteriorly by granules or 

 granulated ridges, and inay even be obliterated by the latter, as shown in the 

 figure already cited. The carina on the occipital process is usually sharp, rarely 



