32 



U. S. p. R. R. EXP. AND SURVEYS ZOOLOGY — GENERAL REPORT. 



lary extends to a vertical line drawn posteriorly to the orbit. There is a great disproportion in 

 the size of the scales which cover the cheeks and the opercular apparatus, being a good deal the 

 smallest on the cheeks. Finally, the position of the ventral fins, and that of the anus, differ 

 from their situation in tlic other species. 



The head enters four times and a half in the total length ; it is sub-conical, with the snout 

 rounded and the jaws equal, or nearly so. In large specimens the lips become verj'' fleshy, and, 

 if any difference be observed in the respective length of the jaws, the upper one will be found 

 slightly protruding beyond the lower. The tongue is smooth. The eye is sub-elliptical, and of 

 moderate development, its horizontal diameter entering about seven times in the length of the 

 side of the head. Both nostrils are nearer the orbit than the extremity of the snout. The 

 convex and external edge of the preopercle is serrated or denticulated. A single flattened 

 spine may be observed upon the opercle. 



The origin of the first dorsal is situated a little in advance of the insertion of the ventrals 

 and backwards of the base of the pectoral fins. It is as high as the second dorsal, but longer 

 upon its base, than the latter. The caudal fin enters about six times in the total length. The 

 anal is as deep as the second dorsal is high, though a good deal shorter. 



Br. VII : VII ; D XIII, 20 ; A 15 ; C 5, 1, 8, 7, 1, 4 ; V I, 5 . P 13. 

 " XII " 13 " " 14. 



The scales are of moderate development, deeper than long, except in the lateral line. They 

 are minutely pectinated upon their posterior section. Sub-truncated anteriorly, they are rounded 

 upon the remaining three edges. Diverging furrows are observed upon the anterior section 

 only. The base of the soft portion of both the second dorsal and anal fins, as also the caudal 

 to a great extent, are covered with scales. The cranial region is likewise scaly. 



The ground color of the dorsal region is reddish olive, olivaceous upon the sides, and yellowish 

 or whitish beneath. The back and upper part of the flanks are spotted or blotched with black 

 or brown. The belly and inferior surface of the tail are unicolor. The side of the head is 

 mottled or barred in the young, in which we also observe upon the dorsal region, iu addition to 

 the marking already alluded to, three transversely oblique and large blotches. The pectorals 

 are spotted with black upon their base, otherwise they are unicolor, yellowish, like the ventrals 

 and anal. The dorsals and caudal are transversely spotted with black. 



References to the figures. — Plate XI, fig. 5, represents Stizostedion horeus, somewhat reduced 

 in size. Fig. 6 is a scale from the dorsal region. Fig. V, a scale from the lateral line. Fig. 

 8, a scale from the abdominal region. 



List of specimens. 



.a 



a 



e3 



385 

 386 

 510 



Locality. 



Fort Sarpy, Nebraska 

 Mil river, Missouri.. 

 Fort Union, Missouri. 



1854 

 1853 

 1856 



■Whence obtained. 



Colonel Vauglian 



Governor Stevens 



Lieut. G. K. Warron. 



N^ature of specimens. 



Collected bv- 



Alcoliolic 

 Jo.. 



.do. 



Dr. Haydea. 

 Dr. Sucliley. 

 Dr. Hay den. 



