146 DR. A. GUNTHER ON A NEW CHARACINOIU FISH. [Feb. 6, 



transverse rows. Upper and lateral parts of the head nearly uni- 

 form brownish black. Mandible with traces of the cross bands 

 •usually observed in H. salvator. Tail black, with numerous scales 

 yellow ; its terminal portion with very broad black bands. Most of 

 the scales of the fore legs are yellow, of the hind legs black. Lower 

 parts yellow, faintly reticulated with blackish. 

 The specimen is 50 inches long. 



5. On a new Genus of Characinoid Fishes from Demerara. 

 By Dr. Albert Gunther, F.R.S., F.Z.S. 



[Received January 26, 1872.] 



A small collection of fishes made at Goedverwagting, a plantation 

 on the coast of Demerara, and presented by F. J. B. Beckford, Esq., 

 to the British Museum, contained an example of an apparently new 

 genus allied to Lebiasina, but with a totally different form of the 

 snout and mouth. It may be characterized as follows : — 



NANNOSTOMUS; 



Dorsal fin placed nearly in the middle of the length of the body ; 

 adipose fin none ; anal short ; ventrals below the dorsal ; caudal 

 deeply forked. Body oblong, covered with large scales; lateral line 

 none. Head of moderate size ; snout subcorneal, with the mouth 

 very narrow, quite anterior. Cheeks narrow, covered by the infra- 

 orbital bones. Both jaws armed with a single series of closely set, 

 compressed, creuulated teeth. Palatine teeth 1 * 



Nannostomtjs beckfordi. 



D. 8. A. 10. L. lat. 22. L. transv. 6. 



Body compressed, its depth being equal to the length of the head, 

 which is one fourth of the total (without caudal). Eye but a little 

 less than one third of the length of the head, and nearly equal to 

 the extent of the snout. Origin of the dorsal and ventral fins in the 

 middle of the length (without caudal). A silvery band along the 

 middle of the side, bordered above by a reddish, and below by a 

 blackish baud. A black spot on the lower half of the gill-cover. 

 Caudal fin red. 



Total length 30 millims. 



* The typical specimen being unique and very email, it did not appear to be 

 advisable to destroy the snout by dissection. I have no doubt Mr. Beckford will 

 succeed in obtaining more examples, from which the details of the dentition can 

 be ascertained. 



