SCIENTIFIC SURVEY. 53 



Sub-class Ganoidei, (Ag.) Muller. Order Chondrostei, Midler. 



Sturionoids. 

 Acipenser oxyrhynchus, Mitchell, Sturgeon. 



Sub-class Elasmobranchii, Bona. Order Plagiostomi, Guv. 



Sab-order Squali, (MuUer) Gill. 



Cetorhinoids. 

 Cetorhiuus maximus (?) Blaiiwille, Basking shark. • 



SCYMNOIDS. 



Somniosus brevipennis, Lesueur, Sleeper. 



Sub-class Dermopteri, Owen. Order Hyperoartti, Bona. 



Petromyzontoids, Bona. 

 Petromyzon Americanus, Les., Lamper eel. 



Familiar and Scientific Description of some of the Maine Fishes 

 named in the foregoing Synopsis. 



Sub-class Teleostel Order Teleocephali. 



Sub-order Physoclisti. 



Family Percoid^.* Sub-family Percix^. 



Family Characters. Body more or less elongated ; in most cases 

 protected by pectinated scales, generally rough to the touch, occa- 

 sionally smooth, owing to the deciduous nature of their prickles. 



Head. — The preopercle and opercle exhibit various spinous or 

 serrated edges, — in a few they are smooth. Jaws, front of vomer, 

 and often the palatine bones furnished with teeth of various kinds, 

 velvet-like, card-like, or of the canine type ; the canines occurring, 

 occasionally intermixed with the former two kinds. 



Fins. — Dorsals always well developed, sometimes single, at oth- 



* In this description it is tliought best to commence with the more perfected orders 

 and proceed to the lo-wer p;rades. Some of them I have described in full, in the form 

 and manner that it is intended all of them shall be in the final report. . Others, 

 merely the family and generic characteristics are given, and in a few even these are 

 omitted because either some doubtful points in regard to them need further investi- 

 gation, or I have not the proper authorities to which I could refer in the matter. 



