SOUTH AMERICAN NEMATOGNATHI. 445 



b. Lower caudal lobe not produced, scarcely, if any, longer than the 

 upper; margin of caudal obliquely truncate, a dusky spot at the base 

 of the first dorsal membrane. D. I, 7;. A. 4 or 5; Lat. 1. 24. 



c. Eye 6-7 in the head; preopercular spine 11-15; median tentacles 

 of the male profusely branched, a small granular patch on the 

 breast below the base of the pectoral; faded. chayresi 436. 



cc. Ej r e 7-10 in the head; preopercular spines 25 or more; median 

 tentacles of the male flattened, mostly simple; breast entirely naked; 

 head broad, depressed; dark brown, thickly covered with light spots 

 which are smallest and most regular on the head; ventral surface 

 lighter. Fins dark brown, irregularly spotted with light. 



stif/maticus 437. 

 bb. Lower caudal lobe decidedly longer than the upper. 



d. Head longer than broad. 



e. Outer caudal rays produced; caudal emarginate. 



f. D. I, 7, rarely I, 8; upper and lower caudal rays produced; 9 to 

 12 interopercular spines; eye 3-3| in the interorbital. 6|-7 in 

 the head; median tentacles of the male simple, rarely bifid; 

 lateral scutes with strong marginal spines, a minute granular 

 plate on the breast below the base of the pectoral spine. Dark 

 brown, everywhere covered with rather large light spots; a 

 dark spot on the base of the first dorsal membrane, the remain- 

 der usually plain dusky; dorsal otherwise dark brown with 

 wavy, interrupted horizontal bands, other fins spotted with 

 lighter. Head 2|-3; Lat. 1. 24-25. cirrhosus 438. 



ff. D. I, 7; dorsal surface dark brown, with two darker cross 

 bands; head irregularly marbled; the color of the body and head 

 much as in Chcetostomus guairensis; ventral surface and fins 

 colored as in cirrhosus, other characters agreeing with those of 

 cirrhosus. cirrhosus dubius 438a. 



fff. D. I, 7; upper and lower caudal rays produced; 9-12 inter- 

 opercular spines; eye 3-4 in the Interorbital, 7 in the head; 

 light or dark brown, everywhere covered with white dots which 

 are largest on the belly; fins colored like the body; a dusky 

 spot on the base of the first dorsal membrane. Head 2i-2. 



leucostictus 439. 

 ee. Outer caudal rays not produced. 



g. D.I, 7; dark brown, ventral surface lighter, everywhere with 

 small lighter spots very closely crowded and scarcely evident 

 on the dorsal surface; fins dusky, obscurely marbled; Lat. 1. 23; 

 head 3. hoployenys 440. 



(jfj. D. I, 8-9, rarely I, 7. Dark brown, sometimes everywhere 

 with dark spots which occasionally have a white center; fins 

 dusky, the base of the dorsal obscurely spotted like the body. 



temminkii 441. 



