450 PROCEEDINGS OF THE ACADEMY OF [Oct., 



thick, fleshy, pointed and tip little free. Interorbital space rather 

 broad and evenly convex. Gill-opening forward to front of eye. 

 Rakers 19 + 41, longest about f of filaments which are f of eye. Scales 

 all well striated. Tubes in lateral line arborescent and rather long. 

 Color in alcohol brassy-brown, back darker than lower surface. Upper 

 surface of head brownish, sides and below pale or more brassy. Pec- 

 toral and dorsal dusted brownish, caudal paler. Ventral and anal 

 whitish. Iris brassy-brown. Length 7^ inches. Demarara River, 

 British Guiana. E. D. Cope. 



This species has apparently been confused, and it is not improbable 

 that Chalcinus rotundatus (Jardine) may be found really the name 

 applicable. Jardine's figure and account are, however, too crude and 

 incomplete to permit of certain identification. In fact the anterior 

 position of the dorsal fin as indicated by the figure would point more to 

 C. angulatus (Agassiz). Under C. hrachipomus, the statement '*la 

 dorsale est assez reculee sur la dos et presque opposee a I'anale qui 

 est longue et basse" by Valenciennes, may perhaps be better referred to 

 that designated as C. hrachy-pomus by Dr. Giinther. I see no reason 

 for Prof. Garman indicating Dr. Giinther's examples as identical with 

 the one from the Amazons under a new name, which is afterwards 

 accepted by Dr. and Mrs. Eigenmann. These latter writers, and also 

 Prof. Ulrey, unite Chalceus angulatus Agassiz with Chalcinus hrachi- 

 pomus Valenciennes, a proceeding which I am unable to accept. The 

 latter may be distinguished from the former by the more posterior 

 insertion of the dorsal. 



COSCINOXYRON gen. nov. 

 Type Chalcinus culter Cope. 



Gill-rakers fine, long and numerous on first arch, about 90 to 100. 

 Dorsal inserted well posteriorly, or about last third in length of head 

 and trunk. 



(Ao<7x£vov, sieve; ^updv^ razor ; reference to the gill-rakers and 

 cultrate body.) 



Coscinoxyron culter (Cope). 



Chalcinus culter Cope, Proc. Acad. Nat. Sci. Phila., 1871 (1872), p. 26.5, PI. 

 14, fig. 3. Type, No. 16,672, A. N. S. P. Ambyiacu River. .John 



Hauxwell. Cope, Proc. Amer. Philos. Soc. Phila., XVII, 1877-78 



(May 17, 1878), p. 692. Peruvian Amazon. Prof. J. Orton. 



Width of head 2f in its length ; interorbital space 3^ in head meas- 

 ured from tip of upper jaw. Body strongly compressed. Head 

 well compressed, becoming constricted below. Surface of snout 

 somewhat flattened above. Teeth a little small, those in upper 



