1908.] NATURAL SCIENCES OF PHILADELPHIA. 539 



tide-water if not brackisli. During the late spring and on through the 

 early summer the males assume high coloration. Brilliant pigment 

 of satin-white color is found about the ends of all their fins, the rays 

 of which become somewhat enlarged or swollen, and thus earning for 

 the fish the very appropriate name of silver fin. Tubercles of small 

 size also appear on the upper surface of the body, though disappearing 

 by late summer, along with the brilliant coloring. The females are 

 but rarely tuberculous, and never so brilliant as the males. The 

 young are not brilliantly colored, but are usually to be distinguished 

 by their reticulated scale pattern being made up of fiarrowly imbri- 

 cated scales, though the lateral line is complete. The silver fin some- 

 times collects in large shoals of possibly a thousand or more individuals, 

 and associates sometimes with other small fish. They are equally 

 active throughout the year, in certain localities, and may sometimes 

 be found under the ice. They will usually bite at a small worm or 

 other bait on a small minnow-hook, though of no use as food on account 

 of their small size, the largest I know of not exceeding 4 inches. They 

 are good bait and live well in the aquarium. Only found in the Dela- 

 ware and Susquehanna basins. Closely related to N. whipplii, and 

 differing in the deeper body and larger scales. 



Notropis cornutus (Mitchill). 



Head 3^ to 5; depth 3 to 4f ; D. usually iii, 7, i, rarely iii, 8, i or 

 iii, 6, i; A. usually iii, 8, i, seldom iii, 9, i, rarely iii, 7, i; scales 

 usually about 30, frequently 31, 32, 33, 34, 35 and 36, often 37 to 40 

 and 27 to 29, rarely 25, 26, 41 or 44 + usually 3, frequently 2, rarely 4; 

 scales above 1. 1. usually 8, frequently 7, occasionally 9, rarely 6 or 7; 

 scales below 1. 1. usually 5, seldom 4 or 6, rarely 7; predorsal scales 

 usually 17 or 18, frequently 15, 16, 19 or 20, occasionally 14, sometimes 

 21 or 22, seldom 23 to 25, rarely 12, 13, 26 or 27; snout 2^ to 4 in head ; 

 eye 2^ to 4^; maxillary 2f to 4; interorbital 2^ to 3^; teeth 2, 4-4, 2 

 usually, rarely 2, 4-4, 1. Body compressed, rather deep, predorsal 

 swollen, form more elongate in young. Head compressed, heavy. 

 Muzzle obtuse. Snout convex, length about f its width. Eye small, 

 large in young, circular, rather high. Mouth moderate, little inclined. 

 Jaws about equal. Maxillary to eye in adult. Interorbital well 

 convex. Rakers 2 + 8 short firm points. Predorsal scales usually 

 small and crowxled and narrowly imbricated, or elongated vertically, 

 on costal region. L. 1. complete, well decurved, about midway along 

 caudal peduncle side. Dorsal origin about midway between front 

 nostril and caudal base. Anal origin trifle behind dorsal base. Caudal 

 forked. Pectoral about f to ventral. Ventral inserted little before 



