ON THE ESOCES OF MIDDLE NORTH AMERICA. 



407 



SPHAGOMORUS ERUMEI, GEN. NOV. 



Ilippoglossm erumei, Guv. Psettodes erumei, Gthr. 



This East Indian species has been assigned by Dr. Giinther (Catalogue) to Bennett's 

 genus, Psettodes (Proc. Comm. Zool. Soc, London, 1831, 147), and the West African P. 

 belcheri, Benn., identified with it, with doubt. The Academy Natural Sciences having 

 received from our correspondent, Dr. Thomas Savage, a fine specimen of Psettodes bel- 

 cheri, from the coast of West Africa, I am able to ascertain its generic distinctness from 

 the above mentioned East Indian form, although, as in the case of Drepane and Crypto- 

 smilia, the two are surprisingly similar. The genera differ as follows : 



Sphagomorus, Milci. 

 Maxillary and mandibular teeth simple. 



Vent between the ventral fins. 



Psettodes, Benn. 



Maxillary and mandibular teeth with 



sagittiform or barbed point. 

 Vent much behind the ventral fins. 



The S. erumei has the jaws smooth ; they arc scaled in the P. belcheri ; the lateral line 

 is slightly oblique anteriorly in the latter, in the former distinctly arched. In P. belcheri 

 the caudal fin is scaled to near the tip ; the form of the body is less elevated than in Rich- 

 ardson's figure of the erumei (Voyage Sulphur). The scales of the lateral line, radial 

 formulas, and coloration, are identical with those of the Sphagomorus. 



SUPPLEMENTARY SYNOPSIS 



OF THE ESOCES OF MIDDLE NORTH AMERICA. 



Six species of Esox, inhabiting our waters may be defined as follows. Others have 

 been described, but in such a way as to leave it doubtful whether they really exist. Girard 

 has pointed out the differences in squamation of the head, and the author has given a 

 synopsis of the species* which, however, possesses many defects, owing to the inclusion 

 of species on the basis of imperfect published diagnoses. 



I. Operculum and cheek entirely scaled. 



Dranchiostegal rays 12—13 (14); front grooved. Dorsal radii 2.12—14. 



End of muzzle to pectoral fin shorter than from ventral to pectoral; same to orbit less than from orbit to margin 

 operculum ; scales between ventrals and pectorals larger, 37 rows. fasciatus. 



* Proceedings Academy Natural Sciences, 1865, 79. 



