NATURAL SCIENCES OF PHILADELPHIA. 277 



anterior position to the adipose fin, which the latter do not exhibit, and 

 though Rafinesque assignes fifteen anal rays and mine have 23 and 24, I prefer 

 doubting the infallibility of these statements to giving another name to the 

 Michigan fish ; it is in any case no other described species. 



Noturus flavus. No. 294, Swartz Creek, Genesee Co. 



Sis large specimens, not apparently differing specifically from smaller indi- 

 viduals from the Youghiogheny and Susquehanna Rivers. Some, however, 

 have but nine branchiostegals instead of ten in the eastern specimens. 

 The orifice of the duct of the poison gland* is irregular in position, being some- 

 times at the base of the posterior pectoral rays, and sometimes even on the 

 side behind the fin, besides in its normal location below the scapular process. 

 From it may frequently be drawn a solid gelatinous style ending in a tripod, 

 each limb of which is dichotomously divided into short branches of regular 

 length. 



Teleocephali. 



Eventognathi. 

 Semotilus corpo r ali s, Putnam, not Abbott. Many specimens from near 



New Hudson, Oakland Co., from Swartz Creek, Genesee Co. and from 



Grosse Isle. 

 The Semotilus rhotheus has been regarded by my friend F. W. Putnam, 

 as identical with this species (vid. Bulletin Mus. Comp. Zool.,p. 8,) although 

 I pointed out the differences in my first description (Proc. A. N. S., 1861, p. 

 564,) when I employed the name cataractus for corporalis. The latter 

 occurs sparingly in the tributaries of the Delaware, but is very common in 

 the affluents of the Susquehanna and Ohio. The former is rare west of the 

 Delaware, where it is abundant, and reaches a large size. S. dissimilisf 

 and pallidus are good species from west of the Mississippi. 



Ceratichthys c y c 1 o t i s, % sp. nov. 



Body much compressed, dorsally flat ; the height 4 2-5ths in. total length. 

 Muzzle obtuse, rounded ; head entering 4^ times in length (to emargination 



* Vid. Gunther Catal. Siluiidne, Brit. Mus. 1864. 



t Of au allied genus, Pogonichthys, Dr. Hammond brought from near Bridger's Pass, an unde- 

 gcribed species. It may bo called P. ( Platygobio) gulonellus. It may be compared with the 



P. communis as follows : 



communis. gulonellus. 



Ventrals acuminate, reaching anus. Ventrals truncate, falling far short of anus. 



Anal longer, with eleven rays. Anal shorter, nine rays. 



Breadth between eyes more than half the top of Breadth between eyes scarcely half length of cra- 



tlie cranium, and more than the height of nium above, equal height of operculum. 



operculum. 



Head 4^ times in length to caudal emargination; eye 5| times in length of head. Scales ^48. 

 Fins D. 1-8 ; C. 19 ; V. 1-8 ; P. 16. From caudal to front base of anal, 2 in. 10 1. Total length, 6 in. 

 3 lines. Above ruddy ash, a faint longitudinal dark band on one row of scales above lateral line. 

 Below yellowish white, lips and chin yellow; suborbital region ruddy. 



JTo Ceratichthys must probably be referred the Leueiscus d i s s i m i 1 i s Kirtld., a common fish 

 in the tributaries of the Ohio. The general appearance differs considerably from that of th other 

 species, especially in the mor prominent muzzle, and, therefore, inferior mouth; but I find no 

 ordinary characters indicating a different genus. 



Ceratichthys micropogon is a species sent me by Jabob Stauffer, Secretary of the Linnaean 

 Society, of Lancaster, and was taken in the Oonestoga by a member of the Society, on one of its 

 excursions. The appearance of the head of this fish is that of a Hypsilepis rather than of a chub, 

 and the difficulty of discerning the minute barbels increases the liability to err in determining its 

 affinities. Mouth slightly oblique, angle opposite anterior border of orbit. Latter enters 3y times in 

 length of bead, which is measured 3 J times in length from muzzle to base of tail. The greatest depth 

 is measured 4 times in the same distance. Head broad, muzzle obtuse, profile rounded descending. 

 Caudal peduncle long. Scales, as in C. biguttatus, |?40. Teeth 4 4, without proper masticatory 



surface, the posterior considerably hooked. Length, from origin of tail to anterior base of dorsal 

 equal from dorsal to posterior nostril. Kays. D. 1-8; C. 9; A.l 7; V. 8 ; P. 13. Above pale 

 yellowish brown; a broad brown Bhade from end of muzzle to base of tail ; below pale yellowish. 

 Length, 3 in. 6 lin. 



1864.] 



