SYLLAEMUS LATIFEONS. 703 



Measurements. 



M. 



Length of specimen to base of ventral fin 0.205 



Length of specimen to base of dorsal fin 0.090 



Length of specimen to base of pectoral fin 0.075 



Length of specimen to edge of operculum 0.071 



Length of specimen to edge of preoperculum 0.055 



Length of specimen to condyle of quadrate 0.029 



Length of specimen to orbit. . 0.017 



Diameter of front between orbits. . 0.020 



Diameter of body at middle of dorsal fin . . 0.045 



Depth of body at middle of dorsal fin . . ........ 0.050 



The specimen which represents this fish in the collections of the sur- 

 vey west of the one hundredth meridian was secured by Lieut. W. L. Mar- 

 shall, of the expedition, and is said to be from near the summit of Pike's 

 Peak, as he informs us. This locality is not its proper horizon, but the matrix 

 which includes it is that of the Cretaceous or Jurassic beds exposed at the 

 eastern base of that mountain. From these it was doubtless procured and 

 carried to the locality where it was discovered. 



