222 NEW SPECIES OF FISHES. (May 



Descriptions of several Kexv Species of North American 

 Fishes. By C A, Le Sueur. Read March 3, 1818. 



THE FIRST ORDER OF FISHES, OR CHONDROP- 

 TERIGIOUS. CuviER. 



Branchiae fixed. 



Second family, or the Selacietis — Pl agiostomes. Dii- 



meril. 



Near Marblehead, in Massachusetts, the fishermen 

 take a kind of shark which they call Nurse or Sleeper, 

 doubtless from its inactive or sluggish habits. It is con- 

 sidered as rare on their coast. From a skin recently pre- 

 pared by them, I have been enabled to make the follow- 

 ing observations. 



This individual, I think, belongs to a new subgenus, 

 allied to the genus Aiguillats (Spinax, Cuv.) which I 

 shall call Somniosus, or the Sleepers. Like Spinax 

 they have spiracles, no anal fins, five small branchial 

 apertures, approximating, and near the pectorals, but 

 they difier in having a short obtuse snout. Pectoral, 

 ventral and dorsal fins very small; dorsals without spines, 

 caudal as in Aiguillats. 



Somniosus brevipinna. Lateral line black , undulat- 

 ing at the head, and marked in its whole length with small 

 transverse lines; tail wide, emarginate; the first dorsal 

 midway between the pectoral and anal fins, the second 

 a little further than the ventral, and both very neai* 

 the tail. 



