ICHTHYOLCGY 



49 





Plate XXVIII, fig. 5, represents Agosia chrysog aster, size of life ; fig. 6 being a scale from 



1 



region. 





List of specimens. 







Catal. Cor'g No. No. of 



No. 



of teeth. 



81 



2684 



spec 



Age. 



8 



Locality 



When 

 collected. 



Whence obtained 



Adult. 



Rio Santa Cruz, Sonora.. 



1851 



Col. J. D. Graham.... 



Nature of 

 pecimen. 



Collected by 



Alcoholic. 



Jno. H. Clark. . 



2. AGOSIA METALLICA, Grd. 



Plate XXVIII, Figs. 1—4. 



Spec. Char. — This species is somewhat shorter than the preceding one. It is very characteristic, and easily distinguished 

 from its congener. The head is shorter and the snout more abruptly rounded. The eye is smaller also. The body is more 

 gracefully sub-fusiform and compressed. The dorsal is higher and narrower, rounded superiorly. The posterior margin of the 

 caudal is crescentic, less furcated than in Jl. chrysogaster. 



Syn. — Agosia metallica, Grd. in Proc. Acad. Nat. Sc. Philad. VIII, 1856, 187. 



The formula of the fins' rajs present also some differences : 



D 9 ; A 8 ; 4,1,9,8,1,5; V 8 ; P 15. 



The same is true with regard to the rudiment at the anterior margin of the dorsal and anal 

 fins, and which must be sought for under the skin. 



The scales are but slightly longer than deep, rather tapering posteriorly, giving to their 

 outlines a somewhat ovoid appearance. 



Upper regions greyish brown, dotted with black ; inferiorly silvery and unicolor ; a black 

 streak on the sides separating the two tints. 



Plate XXVIII, fig. 1, represents Agosia metallica, size of life ; fig. 2 is a dorsal scale ; fig, 

 3, a scale from the lateral line ; and, fig. 4, a scale from the abdominal region. 



List of specimens. 



Catal. Cor. No. 



No. of teeth. 



85 



Age. 



Locality. 



When col- 



lected. 



Whence obtained 



Adult Rio San Pedro, trib. of Gila. 



1851 



Col. J. D. Graham ... 



Nature of Collected by 



specimen 



A •holic. Jno. H. Clark ... 



GOBIO AESTIVALIS, Grd. 

 U. S. P. R. B. tfxpl. & Surveys— Fishes.— Plate LVII, Figs. 17—29. 



Spec Char.— Head contained about four times and a half in the total length. Differs from G.gelidus and 0. vernalis, its 

 American congeners, by a rather compressed body, elevated and arched upon its middle region and tapering rapidly towards the 

 peduncle of the tail. The snout is more protruding thau in G. gtlidus, the eye larger, and the ventral fins inserted sumewhat more 



forwards. 





Stn.— Gobio aestivalis, GnD. in Proc. Acad. Nat. Sc. Pliilad. VIII, 1866, I 39. 



7 



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