228 PROCEEDINGS OF THE ACADEMY OF [Apr., 



Peters/^ from Cameroon, agreeing in the few gill-rakers, concealed 

 clavicles, dorsal rays, and width of the head. It differs, however, 

 in the much longer barbels, fewer anal rays, longer pectoral and 

 caudal fins, and in the caudal showing traces of about three somewhat 

 irregular darker transverse bars. 



(Named for Paul B. DuChaillu, who many years ago collected 

 fishes in the Gaboon Country.) 



Phagorus nieuhofii (Valenciennes). 



One from Borneo. 

 Channallabes apus (Gunther). 



Two from Lubuzi River at Kuka Muno in Chiloango, West Africa. 

 Saccobranchus fossilis (Bloeh). 

 Ganges River, India. 



HOLOGENEID^. 

 Hologenes marmoratus (Gunther). 

 Holmia, British Guiana. 



HYPOPHTHALMID^. 

 Hypophthalmus edentatus (Agassiz). ^ 



Peruvian Amazon. 



PYGIDIID^. 



CETOPSIN^. 

 Hemicetopsis candiru (Agassiz). 

 Peruvian Amazon. 



Cetopsis COeCUtiens (Lichtenstein). 



Ambyiacu River, and Amazon between mouth of Rio Negro and 

 Peru. 



PYGIDIIN^. 

 Hatclieria areolata (Valenciennes). 



Arroyo Comajo, Neuquen, Argentina. 



Pygidium rivulatum (Valenciennes). 



Trichomyderus pardus Cope, Proc. Acad. Nat. Sci. Phila., 1874, p. 132. 

 Upper Amazon. 



Nos. 21,180 to 202, A. N. S. P., cotypes of T. pardus Cope. Jeque- 

 tepeque, Peru. J. Orton. 



Also many examples from Lake Titicaca, Tinta, sources of the 

 Ucayali at Urubamba, and the Rio Urubamba at Urubamba, Peru. 



" Sitz. Ges. Naturf. Fr. Berlin, 18S2, p. 74. 



