34 BULLETIN 95, UNITED STATES NATIONAL MUSEUM. 



&. Head of uniform width; width of mouth more than half length of 

 head. Teeth in the anterior series of each jaw compressed. 

 Maxillary barbels reaching beyond base of pectoral. Head and 

 body with numerous dark spots. Head 7; D. 9; A. 7. (Kner 



and Steindachner.) laUceps, p. 35. 



b'. First ray of pectoral not prolonged ; none of the barbels reaching gill- 

 opening. 



c\ Dorsal 11 or 12 ; A. 9 or 10 oroyae, p. 35. 



cl D. 8; A. 6 or 7 gwec/iworMwi, p. 36. 



a^. Dorsal entirely in front of the anal ; caudal emarginate. 



6\ Dorsal behind the base of the ventrals ; head longer than broad by a 

 diameter of the eye. 



&. Spots as large as or larger than the eye dispar, p. 35. 



c\ Spots much smaller than the eye punctulatum, p. 35. 



b\ Dorsal partly over the base of the ventrals ; D. 8 ; A. 12 pardum, p. 36. 



39. PYGIDIUM POEYANUr.1 (Cope). 



Trichoniycterus rivulatus Cope, Proc. Acad. Nat. Sci. Phila., 1874, p. 132 ; 



Arequipa, Peru ; not of Cuvier and Valenciennes. 

 Trichomycterus poeyanus Cope, Proc. Amer. Philos. Soc. 1877, p. 47; 



Arequipa, Peru ; based on specimens in previous reference. 

 Pygidium poeyanum Eigenmann and Eigenmann, Nematognathi, 1890, p. 



326. 



40. PYGIDIUM RIVULATUM (Cuvier and Valenciennes). 



Trichomycterus rivulatus Ctjvieb and Valenciennes, Hist. Nat. Poiss., vol. 

 18, 1846, p. 495; Guasacona. — GtJNTHER, Cat. Fish. Brit. Mus., vol. 5, 

 1864, p. 274 (copied). — Cope, Proc. Amer. Philos. Soc, vol. 17, 1877, p. 

 47; Lake Titicaca. 



Pygidium rivulatum Eigenmann and Eigenmann, Proc. Oal. Acad. Sci., 

 ser. 2, vol. 2, 1899, p. 51; Cuzco; Moho and Puno on Lake Titicaca. — 

 Eigenmann and Eigenmann, Nematognathi, 1890, p. 330. — Starks, 

 Fishes from Ecuador and Peru, Proc. U. S. Nat. Mus., vol. 30, 1906, 

 p. 771. 



fTrichomycterus incae Cuviee and Valencienin^es, Hist. Nat. Poiss., vol. 18, 

 1846, p. 496; Rio Guatanai at Cuzco. 



Trichomycterus gracilis Cuviee and Valenciennes, Hist. Nat. Poiss., vol, 

 18, 1846; Rio Azangaro near Guasacona; Rio Guatanni near Cuzco; 

 Rio Pontezualo near Coroico ; Lake Compucila near Cuzco. — Cope, Proc. 

 Amer. Philos. Soc, vol. 17, 1877, p. 681 ; Tinta. 



Trichomycterus barbattila Cuviee and Valenciennes, Hist. Nat. Poiss., vol. 

 18, 1846. p. 498 ; Guasacona ; Rio Pontezualo near Coroico. 



Trichomycterus pentlandi Castelnau, Anim. Nouv. Amerique Sud, 1855, 

 p. 49, pi. 24, fig. 1 ; Lake communicating with the Ucayale. 



Trichomycterus pictus Castelnau, Anim. Nouv. Amerique Sud, 1855, 

 p. 59, pi. 24, fig. 2; Lake Titicaca. 



Trichomycterus dispar Gunther, Cat. Fish. Brit. Mus., vol. 5, 1864, p. 273 

 (part) ; Lake Titicaca; Rio de Pontezualo; Andes de la Paz; Guas- 

 acona, Rio de Azangaro. — Garman, Bull. Mus. Comp. Zool., vol. 3, 1875, 

 p. 275 ; Lake Titicaca. 



Habitat : Lake Titicaca ; Ucayale and its tributaries. 



