18S7.] PROCEEDI^'GS OF UNITED STATES NATIONAL MUSEUM. G7 



Perca rhomhoidalis Goode & Bean, Proc. U. S. Nat. Mns., 1>;'5, 20 (not of 

 Liunoius). 



Habitat. — Atlantic aud GuW coasts of the United States. Cape Cod 

 to Cuba. 



This species is very common all along the eastern coast of the United 

 States south of jSTew York and on the Gulf coast as far west as Pensa- 

 cola. 



Its synonymy needs uo remark. 



SMeton.—Y ertehvx 10 -f 14. Occipital crest high and thin, extending 

 to above the anterior part of the eye, the frontal crest being very low. 

 Xo transverse ridge or crest anywhere. A thin crest (temporal) extends 

 back from above the eye past the edge of the skull, the suprascapula 

 being attached some distance in advance of its posterior edge. Skull 

 otherwise smooth. Interorbital area low, depressed, narrowest near the 

 anterior border; its bones thin. A small foramen in the anterior part of 

 the maxillary, the outer coating of the anterior part being thin. Teeth 

 much narrowed towards their base. 



The posterior part of the skull on each side of the occipital crest is 

 higher than in A. prohatocej)halus or A. imimaculatus, and less concave 

 or excavated than in either of these species. 



2. ARCHOSARGUS. 



Archosakgcs Gill, Cauadiau Naturalist, August, 1865 {prohatocephalua). 



Type. — Sparus prohatocephalus Walbaum. 



For reasons already stated, Archosargus is here admitted as a valid 

 genus as distinct from Lagodon on the one baud and Diplodus on the 

 other. The structure of the skulls of A. prohatocephalus and A. iini- 

 maculatus are very much alike; the skulls of the other species of the 

 genus we have been unable to examine. The presence of a procumbent 

 dorsal spine serves to separate both this and the preceding genus from 

 Diplodus. This character is, curiously, confined to American species of 

 Sparince, none of the European tyi^es showing it. 



We recognize three species and one variety as inhabiting our waters. 

 Besides these species Dr. Giinther records Sargus capensis from our 

 waters (Giinther, Shore Fishes, 9, ISSO, Bermudas). The record is some- 

 what doubtful and we omit the species from our list. 



ANALYSIS OF NORTH AMERICAN SPECIES OF ARCHOSARGUS. 



u. Upper jaw with three rows of molars ; second anal spine much larger than third. 

 b. Incisors, i orf ; dorsal spines, 12 or 13. 

 c. Occipital crest broad, its honeycombed structure plainly exposed at its upper 

 margin; dorsal spines 12. Seven broad, black cross-bars, separated 

 by narrower light bars. No distinct shoulder spot. Body much com- 

 pressed; dorsal outline strongly arched; ventral outline almost straight. 

 Profile straight and steep anteriorly. Depth, 2 to 2i in length; head 

 3^. Head compressed, deep; mouth large, almost horizontal ; maxillary 

 2|- in head; eye placed high, 4 in head, 1| in interorbital, IJ in suborbital. 

 Incisors, f ; entire or slightly emarginate, serrate in the young ; molars 



