NATURAL SCIENCES OF PHILADELPHIA. 473 



the lower margin of the opercular apparatus, and extend in a direct course, 

 to the posterior insertion of the anal fin. The dorsal fin has its anterior 

 insertion at the commencement of the posterior third of the total length of the 

 body, and extends to within three-fourths of an inch of the insertion of the 

 caudal fin. The pectoral fin has its insertion immediately behind the margin 

 of the opercle, and the extremities of the rays reach the insertion of the caudal 

 fin. The ventral fins are unusually small, and have their length equal to their 

 width. The anterior insertions of the ventral fins are slightly posterior to the 

 corresponding insertion of the dorsal fin, and its termination is opposite that of 

 the dorsal fin. The caudal fin is deeply furcated, with the lower lobe of the 

 fin one-third longer than the upper. 4 



The numbers of the fin-rays are D, 16. P, 15. V, 6. A, 15. C, 20- 



4 

 Color. In alcoholic specimens, the upper surface of the head and back are 

 deep brown with a purple tint; lower portion of the sides and belly silvery 

 white. The fins and opercle are bright silvery. Iris chestnut-brown. 

 Habitat. Chili. 



Two well preserved specimens of this Ezocetus are in the museum of the 

 Academy, presented by Mr. C. S. Rand. The colors of this species during life 

 are evidently much brighter, giving it an appearance surpassed in beauty by 

 no known species. 



Descriptions of Four New Species of North American Cyprinidae. 

 BY CHARLES C. ABBOTT. 



1. Catostomus Texan u s, Abbott. Spec. char. Head somewhat compressed, 

 large, constituting somewhat more than one-fourth of the total length. Eye 

 small, longitudinally oval ; its longitudinal diameter constituting one-twelfth 

 of the length of the side of the head. Mouth large, with the labial papillae 

 moderately developed. Body moderately compressed ; a dorsal gibbosity extends 

 from the occiput, attaining its greatest height an inch from the occiput, and 

 disappearing at the anterior insertion of the dorsal fin ; it is carinated 

 throughout its whole extent. Dorsal fin one-third longer than high ; its base 

 enters five and a-half times in the total length; its anterior margin equidistant 

 between the base of the caudal and the extremity of the snout. The insertion 

 of the ventrals is opposite the centre of the dorsal fin, and much nearer the 

 base of the caudal than the extremity of the snout. The posterior extremity of 

 the anal fin extends beyond the rudimentary rays of the caudal. The scales 

 are of medium size, with a subcentric nucleus near the anterior margins of 

 their free portions, from which radiate numerous stria?, and around which are 

 numerous well defined ridges. The lateral line is nearly straight throughout 

 its course. 5 



The numbers of the fin-rays are D, 15. P, 16. V, 10. A, 7. C, 18- 



5 



Color. Upper surface of the head, back, and sides, a dull slate color; belly 

 white (not silvery). Throat yellow. 



Total length, 14 inches. 



Habitat. Colorado and New rivers. 



I am indebted to Dr. John L. LeConte, for a note containing a descrip- 

 tion of this fish, noticing many peculiarities which the specimen (a stuffed 

 one) does not now exhibit. 



2. Catostomus chloropteron, Abbott. Spec. char. Body considerably 

 depressed, rapidly tapering posteriorly. The length of the head enters into 

 the entire length of the body four and a-half times. Eye of medium size ; the 

 diameter of the orbit contained in the length of the head eight times. Mouth 



I860.] 



