PEKCOMOEPHI. 89 



11 ; A. II — 11 ; P. 14. Ventral with a very weak spine. The last dorsal 

 spines, as in all the other species, are very short, the anterior ones slender 

 and moderately long ; in this species they are curved. The anal spines are 

 short and slender, the fii'st a rudiment. There are six rows of scales above 

 and six below the vertebral column on the caudal peduncle. 



Measurements, 



M. 



Length of vertebral column 125 



Length of third dorsal spine 025 



Length of ninth dorsal spine 007 



Depth at middle of first dorsal fia 060 



Depth of caudal peduncle 025 



Twin Creek, Wyoming. 



MiOPLOSUS LABRACOIDES CopO. 



Bulletin U. S. Geol. Surv. Terrs., 1877, p. 814. 

 Plate XII, fig. 1. 



This Perch is represented by five specimens, mostly in good preserva- 

 tion. They have much the jDroportions of the Rock-fish. The origins of 

 the pectoral and ventral are in nearly the same vertical line, and that of the 

 first dorsal is not far behind them. That of the first ray of the anal is 

 below the second or third ray of the second dorsal. The rays of none of 

 the fins are prolonged ; the dorsal spines are slender and nearly straight; 

 the longest (third), when depressed, reaches but four-tenths the distance to 

 the first ray of the second dorsal. The last dorsal spine is very short. The 

 soft dorsal rays are rather longer than the spinous. Formulae : — Rays : D. 

 IX— I. 12; C. 8-17-8; A. 11—14; V. I. 5. Vertebrae: D. 10; C. 15. 



The depth at the first dorsal fin enters the total four times ; the depth 

 at the first anal ray enters the length of the vertebral column three times. 

 The length of the head enters the total four times, and that of the orbit 

 enters the head 4 66 times, and into the length of the muzzle one and one- 

 third times. The profile of the top of the head is slightly convex, and the 

 dorsal line is also slightly convex. The mouth opens somewhat obliquely 

 upward. The end of the maxillary bone reaches a point below the middle 

 of the orbit. The teeth of the inferior border of the preoperculum are 

 strong, and are directed forward ; they number five. The angle of the 



