SOUTH AMERICAN NEMATOGNATHI. 109 



b. Top of head flat. Occipital process meeting the dorsal plate. Width 

 of head little less than its length. Eye minute. Snout 5J in head. 

 Intermaxillary band of teeth turned back at the outer edges. Maxil- 

 lary and postmental barbels reaching to the posterior margin of the 

 orbit. Adipose fin 3 in head. Pectoral spine serrate on both margins 



. Caudal rounded. Dorsal fin short. Light brown with darker mark- 

 ings. Head 3; D. I, 6; A. 11. alexandri 73. 

 i. Head moderate, not greatly depressed; teeth villiform. 



c. Intermaxillary band of teeth without a backward projecting angle. 



(BATRACHOGLAN IS) . 



d. Dorsal plate longer than the occipital process. Serration of the 

 pectoral spine strongest on its inner margin. A light bar across 

 the nape from base of pectoral to base of pectoral. parahybce 74. 

 dd. Dorsal plate as long as the occipital process. 



e. Inner and outer margins of the pectoral spine with equally 

 strong teeth. Head at least as broad as long. Eye oval. Maxil- 

 lary barbels reaching to near tip of the pectoral, or shorter. 

 Caudal rounded. Brown, marbled with darker; no distinct cross 

 bands; dorsal, adipose and anal fins blackish-brown with margins 

 of white, the dorsal sometimes with a light cross band near its 

 base; caudal dotted with black, and having, at its tip, a black 

 band which is sometimes edged with white. The markings varia- 

 ble. Head 3; D. I, 6; A. 10-11 (compiled). raninus 75. 

 ee. Inner margin of pectoral spine much more strongly serrated 

 than the outer margin. Head slightly longer than broad, naked 

 above; occipital process short, about equal to dorsal plate, contigu- 

 ous to it. Maxillary barbels reaching base of pectoral, the postmen- 

 tals a little shorter. Eye very small, directed upwards, covered 

 with skin. Intermaxillary band of teeth of moderate breadth, 

 without prolonged lateral portion. Dorsal fin a little higher than 

 long, with strong serrated spine. Length of adipose fin equals 

 about three-fourths its distance from the dorsal. Pectoral spine 

 very stout, depressed. Caudal forked. Pale brownish; head 

 dotted with brown; a wide dark brown band encircling body and 

 covering dorsal fin to a broad margin which is white; tail and 

 caudal dark brown, a large light spot on each side the peduncle 

 (sometimes confluent); two large white spots near base of cau- 

 dal, tip of the fin whitish; adipose fin dark brown, whitish in front 

 and behind; pectoral and ventral with one, anal with two dark 

 brown cross bands. Head 3J; depth 5-9; D. I, 6; A. 9 (Boulen- 

 ger). pulcher 76. 

 cc. Intermaxillary baud of teeth with a backward projecting angle. 



(PSEUDOPIMELODFS . ) 



/. Teeth of the pectoral spine all short, those of the outer margin 

 straight or retrorse, the spine blunt at the end. Depth of the inter- 

 maxillary band of teeth at the middle 3-4 in its width. Outer mar- 



