



ICHTHYOLOGY. 



53 





CODOMA, Girard. 



Gen. Char. — Head short, snout rounded, terminated by a small mouth, the gape of which does not reach a vertical line 



drawn in front of the orbit ; there being no barbels at its angle, and both jaws even. The isthmus is of moderate width. The 



body is more or less elongated, compressed. The insertion of the ventrals is situated in advance of the anterior maro-in of the 



dcrsal. The caudal is furcated, and, like the rest of the fins, rather small. The scales are of modium size, higher than long, 



with radiating furrows upon their posterior section only, and the lateral line is but slightly deflexed upon the thoracic region. 



The pharyngeals are moderately expanded upon their convexity. The teeth are of the raptatorial kind, of the hooked type, 



compressed, without grinding surface, instead of which, a sharp but not serrated ridge. They are arranged upon one single 

 row of four, thus : 4 — 4. 



Syn.— Codoma, Grd. Proc. in Acad. Nat. Sc Philad. VIII, 1856, 194. 



The general physiognomy of the genus reminds us of those of Pimephales and Coclilognathus, 

 with which genera it has no intimate affinities, when the pharyngeal dentition is taken into 

 consideration. Indeed, its affinities with Oyprinella and Montana are of a more close character, 

 for, the teeth are constructed upon the same general pattern ; from Cyprintlla, however, it 

 differs by the presence of one single row of teeth, and from Montana by the absence of serratures 

 upon the cutting edge of the teeth, and finally from both Oyprinella and Montana by smaller 

 scales, the course of the lateral line, and the short and rounded head. 













1. CODOMA ORNATA, Grd. 

 Plate XXIX, Figs. 22—25. 



Spec. Char. — The head, which is short and rounded off, forms the fifth of the total length, whilst the greatest depth enter s 

 in the latter but three times and a half. The eye is circular and well developed ; its diameter entering somewhat more than 

 three times in the length of the side of the head. The anterior margin of the dorsal is a little nearer the extremity of the 

 snout than the insertion of the caudal fin. 



Syn. — Codoma ornata, Grd. in Proc. Acad. Nat. Sc. Philad. VIII, 1856, 195. 



The coloration is rich and profuse, the upper regions are purplish black, with transverse 

 hands of the same hue from the head to the base of the caudal fin ; the space not occupied by 

 these, on the back as well as on the abdomen, is of a golden orange red. The fins are purplish 

 black, edged or tipped with golden yellow or pure white. 



D 1, 8 ; A 1, 7 ; C 6, 1, 9, 8, 1, 6 ; V 1 ; P 12. 



Plate XXIX, fig. 22, represents Codoma ornata, size of life ; fig. 23 is a scale from the 

 dorsal region ; fig. 24, a scale from the lateral line ; and, fig. 25, a scale from the abdominal 



region. 



List of specimens 



Catal. Cor. No. No, of 



No. 



Ao-e. 



of teeth. 



spec. 



91 



2691 



4 



Locality. 



When 

 collected. 



Adult. Chihuahua river and tributaries 



1855 



Whence obtained.' Nature of 



specimen 



Jno. Potts, Esq . 



Alcoholic. 



Collected by 



Jno. Potts, Em 



2. CODOMA VITTATA, Grd. 

 Plate XXIX, Figs. 18—21. 



Spec. Char. — Has a more elongated body and sub-fusiform outline than the preceding species. The head forms a little 

 less than the fifth of the entire length, whilst the depth enters in it about four times and a half. The eye is much smaller than 

 in C. ornata ; the fins and scales are smaller also. 



Syn.— Codoma vitatta, Grd. in Proc. Acad. Nat. Sc. Philad. VIM, 1856, 195. 



