46 



UNITED STATES AND MEXICAN BOUNDARY. 



being furcated. The scales are large, deeper than long, the lateral line following the middle of the flanks. The isthmus is 



rather wide. The pharyngeals have the same shape and form as in Pimephales ; the teeth, however, are more slender and 

 concave upon the grinding surface, giving them the appearance of being bent backwards. They are eultrifjrm, of the grinding 



type, a little more conspicuously hooked, and disposed upon a single row of four : 4 — 4. 



Syn. — Cochlognathus, B. & G. in Proc. Acad. Nat. Sc. Philad. VII, 1854, 150. — Grd. in Proc. Acad. Nat. Sc. Philad. 



VIII, 1856, 181. 



We are acquainted so far with but one species of this genus, referred to hereon. 



COCHLOGNATHUS ORNATUS, B. & G. 



Plate XXXV, Figs. 12—17. 



Spec. Char. — Head forming two-ninths of the entire length; snout abruptly rounded off. Mouth proportionally small; 

 terminal; its gape somewhat oblique. Eyes rather above the medium size ; their diameter being contained four times in the 

 length of the side of the head. Body much compressed, covered with large scales disposed upon twelve longitudinal series across 

 the line of greatest depth. Lateral line deflexed downwards upon the abdomen. Anterior margin of dorsal nearly equidistant 

 between the snout and the rudimentary rays of the caudal. Anal situated entirely backwards of the dorsal. Caudal furcated. 

 Insertion of ventrals situated opposite the anterior margin of dorsal ; tip of pectoral not reaching them. 



Syn. — Cochlognathus omatus, B. &, G. in Proc. Acad. Nat. Sc. Philad. VII, 1854, 158. — Grd. in Proc. Acad. Nat. Sc. 



Philad. VIII, 1856, 181. 



The outline of the scales is quite irregular; they are very much deeper than long, with rather 

 short radiating furrows on their posterior margin only. 



Dl,8; A 6; C 4, 1, 9, 8, 1, 3; V8; P 12. 



The colors, as preserved in alcohol, present a reddish hrown ground, and a dark lateral band 

 or stripe. The dorsal fin exhibits two elongated dark spots — one anteriorly and basal, the other 

 posteriorly and nearer to its tip. The posterior half of the caudal has likewise a darker hue 

 than its anterior and basal half, which is of a dull orange, as is also its extreme margin. 



Plate XXXV, fig. 12, represents Cochlognathus ornatus, size of life ; fig. 13 exhibits the jaws 

 in profile, whilst fig, 14 is a front view of the same, the mouth being open ; fig. 15 is a dorsal 



17 



ion. 



T 

 JU 



1st of specimens. 



Catal. No. 



Cor. No 

 of teeth, 



150 



2728 



No. of 

 spec. 



6 



Ane. 



Locality 



- 



Adult ... 



Brownsville, Te; 



When col- 

 lected. 



1852 



Whence obtained. 



Nature of 

 specimen. 



_ 



Captain Van Vliet 



Alcoholic. 



ALGANSE A TINCELLA, Grd. 

 Plate XXVII, Figs. 1—4. 



Spec. Char.— The scales in this species are next in size to those of A. obesa. There are absut twelve rows beneath, and four- 

 teen above, the lateral iine. I say about, because the specimens are somewhat mutilated, as most market specimens are. The 

 insertion of the ventrals is situated a little posteriorly to the anterior margin of the dorsal. The eye is smaller than in any of 

 the other known species of this genus. 



Syn.— Leuciscus tincella, Valenc in Cut?, fy Val. Hist. nat. des Poiss. XVII, 1854, 323. 



rftgansea tincella, Grd. in Proc. Acad. Nat. Sc. Philad. VIII, 1856, 183. 



The scales are elongated, sub-elliptical, provided with radiating furrows upon their entire 

 periphery. 



