406 EXPLORATIONS ACKOSS THE GREAT BASIN OF UTAH. 



length, and anteriorly, from cheek to cheek, one-tenth being scarcely more than the 

 intei'orbital space. 



The eyes are of moderate size, circnlar, and entirely lateral, bnt near the profile; 

 they are situated anterior to the plane separating the anterior and posterior halves of the 

 head, the suborbital ring being half-way; the diameter of the eye exceeds a sixth of the 

 head's length (five twenty-eighths), and the center of the pupil is distant two diameters 

 from the muzzle. 



The dorsal fin commences midway Ijetween the muzzle and end of the median 

 caudal rays. Its base equals a ninth of the total length, its anterior rays fifteen 

 hundredths, and its last more than six hundi'edths. 



The anal fin commences between the sixth and seventh tenths of the length, is 

 smaller than the dorsal fin, and the disproportion between the anterior and ])osterior 

 rays is less. The base equals an eleventh of the length, the anterior rays thirteen 

 hundredths, and the posterior more than seven hundredths. 



The caudal fin is furcate, and its lobes equal; the median rays constitute a ninth 

 of the total length, and the longest equal a fifth. 



The pectoral fins are rounded, the third and fourth rays being longest; they equal 

 sixteen hundredths of the total lent'-th. 



The ventral fins are also rounded, and the third branched ray longest. They are 

 inserted under the first branched ray of the dorsal; their length equals thirteen hun- 

 dredths of the total. 



The number and character of the rays are indicated by the following formula: 



D. 4. 7 ^ A. 4. 6 ^ C. 9. I. 9. 8. I. 8; P. 1. 14; V. 1. 9. 



All the simple rays of the dorsal and anal fins, except the fourth, are rudimentary. 



The scales are of moderate size, and mostly suborbicular, with the nucleus sub- 

 central, and with numerous radiating striae. The lateral line runs through about fifty 

 or fifty-five, and from the dorsal to the base of the ventral fins there are seventeen 

 rows, ten of which are above and six ]:»elow the lateral line. 



The color is a dark purple or purplish-1:)lue, with each scale margined with darkei-. 

 The fins are of the same color as the body. 



Specimens of this interesting new species were obtained by Mr. C. S. McCarthy, 

 the collector of Captain Simpson's party, in the Salt Lake Basin of Utah. The species 

 is readily distinguishable by the margination of the scales with a darker color. 



Genus PLATYGOBIO, Gill. 



Synonymy. 



PoGONiCHTUVS sp. Gimid, Eesearches ou Cypriuoid Fishes, (sep. copy, p. ^4,) in Proccediuj;s .icademy of Natural 



Sciences of Philadelphia, vol. viii, p. 187, 1856. 



The body is elongated, slender, and sub-fusiform, higliest before the dorsal fin. 

 The caudal peduncle is oblong and rather stout. 



The scales are of large size, and nearly equal on the sides and front of the back; 

 they advance forward nearly to the region above the vertical of the posterior margin 

 of the preoperculum. 



