NATURAL SCIENCES OF PHILADELPHIA. 159 



Pimelodus lemniscalus, in the "Memoires du Museum d'Histoire Naturelle," 

 belongs, truly speaking, to the genus Noturus of Rafinesque, and which was at 

 one time supposed of being founded upon young specimens of Pimelodi, but is 

 now admitted to be a distinct genus, although resembling in its full grown 

 condition the immature state of Pimelodus, properly so called. The genus 

 Noturus is thus made to include a second species under the name of N. Jerri' 

 niscatus. We venture to say that Lesueur's specimens were procured in Penn- 

 sylvania, and not in the southern States, as assumed by Dekay. 



LXVI. The fish described by F. B. Hough, under the name of Pimelodus 

 gracilis, in the Fifth Ann. Rep. of the Reg. of the Univers. of N. Y., 1852, p. 

 26, is a very characteristic species, but its specific name is unfortunately pre- 

 occupied in the genus Pimelodus. We propose, therefore, to designate it in 

 future under the appellation of Pimelodus houghi. We have examined speci- 

 mens collected at Sommerville, St. Lawrence Co., N. Y. by Mr. Hough himself ; 

 others from Foxburgh, Pa., collected by S. F. Baird ; and others still, from 

 Ogdensburg : they are all preserved in the Museum of the Smithsonian Insti- 

 tution. 



LXVII. Dr. Hoy has collected in the neighborhood of Racine, Wis., speci- 

 mens of a species of Pimelodus, which we propose dedicating to him ; hence 

 calling it P. hoyi. The head constitutes a little less than the fourth of the 

 total length, its upper aspect being longer than broad. The upper jaw is some- 

 what longer than the lower one. The eyes are of medium size ; their diameter 

 entering six times and a half in the length of the side of the head, and four 

 times in the interocular space. The anterior margin of the dorsal fin is nearer 

 the apex of the snout than the origin of the adipose fin. The caudal is slightly 

 emarginated, subcrescentic upon its posterior margin ; it constitutes the sixth 

 of the whole length of the fish. The anal fin is deep and rounded off upon its 

 exterior margin ; its base is somewhat less than the fifth of the entire length. 

 The formula of the rays is : D I, 7 ; A 23 ; C 2, 1, 7, 7, 1, 3 ; V 8 ; P I, 9. 

 The specimens observed measure about a foot in total length ; their coloration 

 is of that uniform type common to various species. 



LXVIII. Specimens of a species, more closely allied in its general appear- 

 ance to P. hoyi than any other of its congeners, were caught in Root River, 

 near Racine, Wis., by S. F. Baird. 



The head forms a little more than the fourth of the total length ; its upper 

 aspect is as broad as long. The jaws are equal. The eyes are of medium size, 

 their diameter being contained eight times in the length of the side of the head, 

 and four and a half times along the interocular space. The anterior margin of 

 the dorsal fin is nearer the origin of the adipose than the apex of the snout. 

 The caudal fin, which constitutes the sixth of the total length, is subcrescentic 

 upon its posterior margin. The anal fin is deep and rounded off exteriorly ; its 

 base being contained five and a half times in the entire length. The rays are: 

 D I, 6 ; A 20 ; 3,1,8,8,1,4; V 8 ; P I, 9. 



We propose calling this species Pimelodus confinis. 



LXIX. A small species having the general appearance of Pimelodus cupreus 

 of Rafinesque, was collected by Robert Kennicott, Aux Plaines, 111. The chief 

 distinguishing mark between the two species consists in the relative length of 

 the jaws, the lower one in P. cupreus being shorter than the upper, whilst they 

 are both equal in the species here alluded to, and which we call P. cupreoides. 

 The head forms a little less than the fourth of the total length ; it is as long as 

 broad, and rounded off upon the snout. The eyes are of medium size : their 

 diameter being contained seven times in the length of the side of the head, and 

 about four times along the interocular space. The anterior margin of the dor- 

 sal fin is nearer the snout than the adipose. The caudal is posteriorly rounded 

 off, formiug a little less than the sixth of the entire length, and shorter than 



1859.] 



