300 CALIFORNIA ACADEMY OF SCIENCES. 



ANALYSIS OF THE SPECIES OF AGENEIOSUS. 



a. Caudal forked. 



b. Snout short, scarcely if any longer than the eye; anal rays about 30; 

 branchiostegals 8. 



c. Maxillary barbel not extending beyond the rictus, the basal por- 

 tion fleshy; proh'le strongly concave, the postorbital portion of the 

 head steep. Nearly plain; brown dots on head, back, and base of 

 dorsal fin. brevis 236. 



cc. Maxillary barbel extending beyond the rictus, the basal portion 

 spinous; profile almost straight, scarcely descending. Back pur- 

 plish; top of head with purplish dots, smaller points above the 

 anal; an indistinct dark lateral band; all the fins punctulate; lips 

 black. atronasus 237. 



bb. Snout long and pointed, much longer than the eye; branchiostegals 

 usually 10-11. 



d. Maxillaries terminating in a branched spiny process which pro- 

 jects beyond the anterior margin of the eye; dorsal spines strong, 

 strong hooks on its anterior margin. 



e. Upper jaw projecting beyond the lower valencie.nnesi'23&. 



ee. Lower jaw projecting beyond the upper. armatus 239. 



dd. Maxillaries terminating in a fleshy barbel. 

 /. Head 3-4 in the length. 



g. Posterior margin of the pectoral spine serrate, at least near its 

 tip. D. I, 6. 



h. Maxillary barbel reaching the rictus, its base osseous, some- 

 times with short spines along its upper margin. Dorsal 

 spine very slender, longer than the pectoral spine; serrated 

 on its anterior margin. Upper portion of the head, upper 

 half of the body and caudal yellowish, thickly spotted and 

 marbled with dark violet. Eye 3| in the snout, 8 in head. 

 Head 3f-4; depth 5fo-4J. D. I, 6; A. 39-41. (Steindachiier.) 



caucanus 240. 



hh. Maxillary barbel not reaching the rictus, ventrals about 

 reaching the anal. Br. 10-11. 



i. Depth of the intermaxillary band of teeth in front equals 

 a diameter of the eye; snout long and pointed. Dorsal sur- 

 face dark blue, becoming abruptly pale on the sides. Head 

 3^-4. Eye 3^-4 in snout, 7-J-8 in head. ucayalensis 241. 

 ii. Depth of the intermaxillary band of teeth scarcely more 

 than half as wide as the eye; snout more or less rounded 

 Head 4-4. Eye 2-3 in snout, 5-6 in head, dentatus 242. 

 gg. Posterior margin of the pectoral spine smooth. D. I, 7. Eye 

 its own diameter behind the rictus. Maxillary barbel not at- 

 taining the rictus by its own length. Pectoral spine 3J in 

 head. Ventrals falling far short of anal. Dorsal spine slender, 



