FISHES PERCIDAE CALLIURUS MELANOPS. 



11 



List of specimens. 



CALLIURUS, Rafin. 



Gen. Char. — Body generally elongated and sub-elliptical ; compressed. Head of moderate development. Mouth large ; jaws 

 sub-equal, lower one longest. Velvet-like teeth on the jaws, front of vomer, and palatines. Tongue generally smooth. Cheeks 

 and opercular apparatus scaly. Edge of preopercle occasionally serrated. Branchial apertures continuous under the throat. 

 Spinous portion of dorsal fin longer and lower than the soft portion, with a depression between them. Anal fin with three 

 spiny rays only. Insertion of ventral fins placed behind e base of the pectorals. Caudal fin posteriorly sub-emarginated 

 Scales large, or of moderate development 



Stn.— Coifittrus, Rafin. Ichth. Ohiens. 1820, 26.— Agasb. Amer. Journ. of Sc. XVIII, 1854, 300. 



In general appearance the species of this genus resemble those of Ambloplites very closely ; 

 they are elongated without being slender, and but very seldom short and deep like Bryttus and 

 Pomotis. The only prominent difference between Calliurus and Ambloplites consists in the 

 presence of three anal spines in Calliurus, instead of five, as is the case in Ambloplites. From 

 Dioplites it differs by the two dorsal fins not being separated as is the case in the latter. 



The cheeks, as well as the opercular apparatus, are covered with scales, and a black patch 

 marks the posterior portion of the opercle, as in Dioplites, Fomoxis, Ambloplites, Bryttus, and 

 Pomotis. 



1. CALLIURUS MELANOPS, Grd. 



Plate III. 



Spec. Char. — Mouth very large ; cleft directed obliquely upwards. Posterior extremity of maxillary extending to a ver- 

 tical line drawn posteriorly to the orbit. Eye large. Insertion of ventrals situated opposite the base of the pectorals, a 

 little in advance of the origin of the dorsal ; their tips not extending to the vent. Scales very large. Ground color reddish 

 brown, with a blackish spot upon the centre of each scale. A black patch at the upper and posterior margin of the opercle. 

 Soft portion of dorsal and anal spotted at their base. 



SvN. — Calliurus melany>s, Grd. in Proc. Acad. Nat. Sc. Philad. November 1867. 



This species establishes a transition between Ambloplites and Calliurus, and naturalists may 

 place it in either of these genera. It has the general physiognomy of Ambloplites : its large 

 scales, and its teeth upon the tongue ; whilst it approximates Calliurus by the presence of three 

 spiny rays to the anal fin. 



Its form is graceful, elongated, with the dorsal and abdominal outlines regularly curved. 

 The body is quite compressed posteriorly ; the nape is swollen and rounded. The greatest 

 depth is equal to the length of the head, and contained about three times in the total length. 



The head, therefore, constitutes about the third of the total length. The mouth is very large ; 



