48 



UNITED STATES AND MEXICAN BOUNDARY. 



or orange beneath, 



covered all over, the abdominal region 



times radiating furrows tmon the anterior as well as upon the posterior sections ; they are 

 proportionally smaller than in A. osculus, and somewhat more elongated. The ground color is 



yellowish brown above, golden 

 excepted, with small black spots. 



Syn. — Jlrgyreus notabilis, Grd. in Proc. Acad. Nat. Sc. Philad. VIII, 1856, 186. 



Plate XXVII, fig. 5, represents Argyreus notabilis, size of life ; fig. 6 is a scale from the 

 dorsal region ; fig. 7, a scale from the lateral line ; and, fig. 8, a scale from the abdomina 



region. 



List of specimens 



Catal. 

 No. 



Cor'g No. 

 of teeth. 



No. of 

 spec. 



Locality. 



49 



26G2 



4 



llio Santa Cruz, Sonora. 



When col- 

 lected. 



Whence obtained. 



Nature of 

 specimen. 



1851 



Collected by 



Col. J. D. Graham .. Alcoholic' John H. Clark 



AGOSIA, Girard. 



Gen. Char. — Snout rounded, slightly protruding beyond the lower jaw, though the mouth opens horizontally. The mouth 

 is of medium size, surrounded with narrow and smooth lips, and provided upon its angle with a very small barbel. The isthmus 

 is of moderate width. The insertion of ventrals is situated opposite the anterior margin of dorsal fin, which is higher than long. 

 The caudal is furcated. The scales are minute, somewhat longer than deep, with radiating furrows all around. The pharyngeal 

 bones are expanded upon their curvature. The teeth are of the prehensile kind, of the hooked type, provided with a grinding 

 surface, strongly hooked, and disposed thus: 4 — 4, that is, upon one single row of four. 



Syn. —Jgosia, Grd. in Proc. Acad. Nat. Sc. Philad. VIII, 1856, 186. 



Now, comparing the above with the characters assigned elsewhere to Argyreus , we find that the 

 most prominent difference resides in the pharyngeal teeth. The isthmus is narrower also, and the 

 insertion of the ventrals placed further backwards. 



1. AGOSIA CHRYSOGASTER, Grd. 



Plate XXVIII, Figs. 5— 8. 



Spec. Char.— Head forming a little more than the fifth of the total length. The posterior extremity of the maxillary extends 

 to the vertical line of the anterior rim of the orbit. The eye is large and circular ; its diameter being contained about four times 

 in the length of the side of the head. The anterior margin of the dorsal is somewhat nearer the extremity of the snout than the 

 insertion of the caudal fin. 



Syn.-— Jgosia chrysogaster, Grd. in Proc. Acad. Nat Sc. Philad. VIII, 1856, 187. 



A minute rudimentary ray at the anterior margin of both the dorsal and the anal fins is not 

 included in the following numbers, 



D 10 ; A 7 ; C 4, 1, 9, 8, 1, 5 ; Y 9 ; P 16. 



The scales are obscurely sub-quadrangular, conspicuously longer than deep, with a proclivity 

 of being deeper posteriorly than anteriorly. 



The region above the middle of the flanks is reddish brown, spotted or dotted with black, 

 especially upon the head ; a black streak separates this region from that beneath, which is 

 iniicolor, of a golden hue. 



