8 U. S. p. K R. EXP. AND SURVEYS ZOOLOGY GENERAL REPORT. 



AMBL( PLITES, Rafin. 



Gen.Char.— Body compressed ; dorsal and ventral outlines sub-depressed. Head large. Moulli large also; lower jaw longest. 

 Velvet-like teeth on the jaws, the vomer, palatines, and tongue. Cheeks and opercular apparatus scaly. Branchial apertures 

 continuous under the throat. Spinous portion of dorsal fin lower than the soft, and extends upon a longer hase. Anal fin 

 provided with five or more spiny rays. Insertion of ventral fins a little behind the base of the pectorals. Caudal fin posteriorly 

 8ub-concavo. Scales well develo; ed, and generally ciliated posteriorly. 



Sm.—Jtm'iloplites, Rafin. Ichth. Ohiens. 1820, 33.— Agass. Amcr. Journ. of Sc. XVll, 1854, 299. 



This genus is very closely allied to the preceding one, from which it is to be distinguished by 

 the conformation of its dorsal fin. The latter is composed of a greater number of spiny rays, 

 occupying a base of a greater extent than the soft and articulated rays. The spines themselves 

 are lower than the soft rays, so that a kind of depression may be said to exist between the two 

 portions of that fin. 



Two species are referred to this genus, A. ichlheloides and A. aeneus. Of the latter we give 

 the following figure and description. 



1. AMBLOPLITES ^NEUS, Agass. 



Rock Bass, 6iC. 



Plate 1. 



Spec Char. — Posterior extremity of maxillary extending to a vertical line intersecting the pupil. Insertion of ventrals oppo- 

 site the base of the pectorals. Anterior spiny rav of anal fin under the ninth dorsal one. Posterior margin of caudal fin slightly 

 emarginated. Upper regions of head and body of a coppery brown ; inferior regions, yellowish brown. 



Sxti.—Cichla ccnea, Lesu. Journ. Acad. Nat. Sc. I, 1822, 214, fig.— Kirtl. Rep. Zool. Ohio, 168, 191. 



Centrarckiis aeneus, Cuv. & Val. Hist. Nat. Poiss. Ill, 1829, 84.— Rich. Faun. Dor. Amer. HI, 1836, 18. PI. Ixxv.— 



DeKav, New Y. Fauna, 1842, 27, PI. ii, fig 4.— Kirtl. Bost. Jour. Nat. Hist. IV. 1842, 229. PI. xi, fig. L 



Storer, Synops. 1646, 37. 

 Rock Bass, GoggU-eyed Bass, Black Sun Fisli, Vernacular. 



The general aspect of this species is sub-elliptical when seen in profile ; the dorsal and 

 abdominal outlines being sub-depressed. The greatest depth of the body is more than the third 

 of the total length. The greatest thickness holds the same relations towards the depth as the 

 latter holds towards the length. 



The head is very large, though constituting something less than the third of the total length. 

 Its occipito-frontal declivity is gradual towards the snout, which assumes a wedge-shaped 

 appearance upon the plate. The lower jaw is longest and protrudes slightly beyond the upper. 

 The cleft of the mouth is large and obliquely directed upwards. The posterior extremity of the 

 maxillary extends to a vertical line intersecting the pupil. 



The tongue is very large and fleshy, bearing a sub-elliptical patch of velvet-like teeth almost 

 as conspicuous as those situated upon the palatine bones, the front of the vomer, and upon the 

 jaws. The eye is large and circular ; its diameter entering nearly four times and a half in the 

 length of the side of the head. The anterior nostril is equidistant between the anterior rim of 

 the orbit and the margin of the upper jaw ; the posterior nostril is equal in development with 

 the former and lies between it and the orbit. The external margin of the opercular bones is 

 without spines or serratures of any kind ; the opercle, sub-opercle, and inter-opercle are covered 

 with scales considerably larger than those which may be observed on the checks. The branchial 

 apertures are continuous under the throat ; there are six branchial rays. 



