328 CALIFORNIA ACADEMY OF SCIENCES. 



mm. Back and sides uniform yellowish or brownish. 



q. Eye comparatively large; maxillary barbel not reaching to 

 gill-opening. immaculatum 270. 



77. Eye minute, smaller than the posterior nares, maxillary 

 barbel reaching beyond base of pectoral. (Steiiidachuer.) 



taczanowskii 271. 



dd. First dorsal ray prolonged in a filament; barbels scarcely extend- 

 ing beyond the eyes; caudal truncate. Blackish, lighter below. D. 11; 

 A. 10. (Cuvier & Valenciennes.) niyricans 272. 



aa. Origin of the dorsal over the origin of the anal; eye large, in anterior 

 half of head; upper maxillary barbel reaching beyond base of pectoral. 

 Caudal rounded; first pectoral ray prolonged. Chocolate brown; in- 

 distinct spots on the caudal peduncle; dorsal and caudal rays dotted 

 with violet. Head 7; D. 8; A. 7. (Steindachner.) amazonicum 273. 



257, Pygidium macraei, 



Thricomycterus macrcei Girard, U. S. Naval & Astron. Exped. ii, 

 245, 1855 (Uspullata(?) east side of the Cordilleras at an eleva- 

 tion of 7,000 feet). 



Pygidium macrcei E. & E. Proc. Cal. Acad. Sci. 2d Ser. ii, 51, 1889 

 (Uspullatuo). 



Habitat: Eastern slopes of Central Chile. 



The single specimen, No. 8,298, of this species was 

 presented to the Mus. Comp. Zool. by the Smithsonian 

 Institution in 1859. It came from " Uspullatuo " and is 

 most likely Girard's type. 



Elongate, rather compressed, especially backward. 

 Head as broad as long, snout rounded; eye small, mid- 

 way between tip of snout and end of opercle; none of 

 the barbels reaching the gill-opening. 



Gill-opening scarcely continued forward below; joined 

 to the isthmus for a distance equal to half the width of 

 the mouth. 



Pectorals obliquely truncate, the first ray not pro- 

 duced; origin of dorsal some distance behind the ventrals, 

 equidistant from occiput and tip of caudal; fourth or 

 fifth dorsal ray highest, then gradually decreasing in 

 height to the last. Caudal emarginate, the upper lobe 

 pointed, the lower rounded. Anal inserted below the 

 9th dorsal ray and terminating under the 17th. Ventrals 



