SYNOPSIS OF THE CYPKINIM! OF PENNSYLVANIA. 



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PHOTOGENIS LEUCOPS, Cope. 



Squalius (Glinostomus) photogenis, Cope, Proc. Acad. Nat. Sci., Phila., 1864, 280. 



A species resembling some Alburni in its large caducous scales and attenuated form. Eye 

 one-third head, round. Mouth quite oblique; under jaw scarcely projecting; maxillary not 

 reaching line of margin of orbit. Head entering four and two-thirds times into length to 

 fork of caudal ; greatest depth seven times. Back broad. Fins I), narrow 8 ; C. 19, A. 

 1 — 10. V. little anterior to dorsal 9. P. narrow falcate 13, extending about half way 

 from their origin to that of the vontrals. Scales with radii stronger than concentric lines. 

 From base of caudal to base of first dorsal ray, equal from latter to anterior border of iris. Lateral line deflexed, 

 rising with outline of belly at anal fin. Above pale ochre, with a median brown line, and one on each side, from 

 opercular upper angle to tail. Sides and below bright silvery, especially brilliant on the operculum and suborbital 

 region. Lips blackish edged. Muzzle and chin whitish. Length three inches. 



In two specimens the pharyngeal teeth are arranged 1.4 — 4.1. This bright species 

 occurs, so far as known, in tributaries of the Alleghany lliver only ; those which we possess 

 are from the Youghiogheny. 



It is readily distinguished among our numerous small silvery species, resembling in a 

 slight degree only the Alburncllus rubrifrons. This has a shorter, deeper body, longer 

 muzzle, smaller eye, etc. 



1IYBOPSIS, Agassiz. 



Amer. Journ. Sci. Arts, 1854, 358. Putnam Bullet. Mus. Comp. Zool., No. I, p. 9. 

 lludsonius, Girard, Proc. A. N. Sci., Phila., 1856, 210. Alburnojoe, Girard, 1. c, 194. 



Form elongate, less so than in the Ph. leucops ; scales with the radii distinct 6 — 10, and the concentric lines 

 very strong. Lateral line deflexed anteriorly. Orbit three and one-half times in length of head, equal length 

 muzzle and is three-fourths the intororbital breadth. Head five and one-third times in total length, equal length 

 caudal fin. Muzzle straight above, mandible not projecting when closed, end of maxillary attaining line of orbit. 

 Premaxillary margin opposite middle pupil. Pectorals two-thirds length to ventrals. liases of anal and dorsal 

 fins equal, equal two-thirds height of former, throe-fifths height of latter. First dorsal ray a little nearer origin 

 caudal than end muzzle. Kays, D. 1.8. A. 1.8. V. 7 and 8. P. 13. 



Length 2.875 inches, depth caudal peduncle at middle .19 in. Teeth in numerous specimens 1.4—4.1. 



Color olivaceous, with a plumbeous band along the posterior half the lateral line; thoracic region and lower 

 half the sides of head silvery, remainder of head blackish. Median part of caudal fin, a spot on the upper hinder 

 portion of the dorsal, and a narrow vertebral line, black. 



Many specimens of this species are in Museum Academy, from the St. Josephs River, in Southwestern Michigan. 



This species bears a superficial resemblance to the Hybopsis plumbeolus, but apart from the difference of denti- 

 tion, and the spot on the dorsal fin, this species has a smaller eye, longer ventrals, etc. 



