274 siltjrid^:. 



3. Trichomycterus areolatus. 



Trichomycterus areolatus, Cuv. 8f Vol. xviii. p. 492. 

 ? Thrichomycterus maculatus, Girard, in U. S. Naval Astronom. Exped. 

 Zool. p. 243. pi. 34. figs. 1-3. 



B. 8. D. 13. A. 8. P. 8. V. 5. 



The length of the head is more than the height of the body, and 

 nearly one-seventh of the total. The origin of the dorsal fin is in the 

 middle between the occiput and the end of the caudal fin. None of 

 the pectoral rays are prolonged. Brownish olive, with blackish spots. 



Chile. 



a, b. Adult. Chile. 



4. Trichomycterus nigricans. 

 Cuv. 8f Vol. xviii. p. 494. 



B. 7. D. 11. A. 10. P. 9. V.5. 



Barbels short, scarcely extending beyond the eyes ; the first dorsal 

 ray prolonged into a filament. Uniform blackish above. (Val.) 

 Sta Catharina (Brazil). (Chile?) 



5. Trichomycterus rivulatus. 

 Cuv. 8f Val. xviii. p. 495. 



D. 8. A. 7. 



Nasal and maxillary barbels extending beyond the eye. Brown, 

 with undulated white lines. ( Vol.)' 

 Guasacona. 



6. Trichomycterus taenia. 

 Kner, Sitzgsber. Acad. Wtss. Munch. 1863, p. 228. 

 D. 8. A. 6. 



Head heart-shaped, becoming narrower towards the snout, one- 

 seventh of the total length. Caudal fin truncated. Body with a 

 blackish longitudinal band, above which there are series of dark dots. 

 (Kner.) 



Western Andes of Ecuador. 



7. Trichomycterus laticeps. 

 Kner, I. c. 



D. 9. A. 7. 



Head much depressed, subquadrangular, one-seventh of the total 

 length ; the width of the mouth is more than one-half of the length of 

 the head. Sides of the trunk with black spots, and with from sixteen 

 to twenty whitish cross-streaks. (Kner.) 



Western Andes of Ecuador. 



