SYNOPSIS OF THE CYPRINIDyE OF PENNSYLVANIA. 



385 



young of the II. bifrenatus and II. procne arc readily separated, since the latter species 

 exhibits its form and its lateral line in specimens of seventeen lines long and upwards, as 

 well as its color. The II. procne is more silvery, and exhibits from the smallest size up- 

 wards a silver lateral band with black specks at the bases of the scales. 



The dentition of these species, like that of the Ilypsilepis kentukiensis, docs not vary 

 from the formula at any age. The lateral line is, however, wanting in both Ilypsilepes, 

 smaller than nine lines, and II. procne below seventeen lines. I am inclined to anticipate 

 that the II. bifrenatus will be found to attain a rather larger size, though most likely 

 one of the smaller Cyprinidoe. My specimens were taken in the beginning of winter. 



IIYBOPSIS PPOCNE, Cope. 

 Hyhognathus procne, Cope, Proc. A. N. S., Phila., 1864, 279. 



This small species may be readily distinguished among others common in our streams 

 by its long caudal peduncle and tail, its large brown-edged dorsal scales, and plumbeous 

 lateral band. 



The dorsal region is compressed and slightly elevated at the dorsal fin, and the muzzle strongly obtuse ; the eye 

 is large and longitudinally oval. Below white tinged with yellow. The bases of the dorsal and anal are five- 

 eighths to one-half the length of the first rays of those fins, and the bony ray of the former is two-thirds the same 

 height. Caudal deeply furcate, and with acute lobes. Kays I). 1, 8 A. 1, 7, constantly one less than in II. oha- 

 lybacus and hudsonius, the last being deeply fissured in the three ; V. 1, 8, reaching vent; I'. 12-13. Fins un- 

 spotted ; a blackish line along origin of anal, and continuation of lateral band on base of caudal. 



This species rarely attains '2.5 inches; a common length is 2.187, of which caudal fin is .437; from middle 

 origin latter to first anal ray .502; end muzzle to origin dorsal .875; this distance is sometimes less than, some- 

 times equal to, from latter point to origin caudal. 



This fish prefers comparatively sluggish waters, and abounds in the streams of the low 

 lands which empty into the ocean and its estuaries. In our hill country it occurs in mill- 

 dams and coves of the larger streams, in fact, in situations not chosen by Argyreus atro- 

 nasus. I have seen it from the Delaware, Schuylkill, White Glay Creek, of the Delaware 

 basin, and Conestoga of the Susquehanna, where Jacob Stauffer originally observed it, 

 but not farther westward. 



I had thought this fish the fry of some larger species, but am now convinced of its small 

 adult age, as being one of the smallest known Cyprinidas. Besides having seen a great 

 number of specimens, I have found females much distended with eggs, an observation 

 also made by my friend, Jesse Ihirk. I have watched them also going through the move- 

 ments of preparing a place of deposit for eggs. 



VOL. MM. 



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