HALECOMORPHI. 745 



The Taxodium nearly resembles that from the shales at Osiiio, Nevada, and 

 on various grounds I suspect that these beds form a part of the "Amyzon 

 Group" (American Naturalist, June, 1880), with the shales of Osino and 

 of the South Park of Colorado. 



PISCES. 



HALECOMORPHI. 



AMIA Linn. 



Two species of this genus have been found in the Amyzon shales. 

 None of the specimens are as large as the Amiidoe ivova the Bridger forma- 

 tion. 



Amia scutata Cope. 



Bulletin U. S. Geol. Survey Terrs., 2d Series, 1875, p. 3. 

 Plate LX : tig. 1. 



Represented by a specimen which lacks the head and body anterior 

 to the middle of the long dorsal fin. The anal and part of the dorsal fin 

 and the heterocercal tail are well displayed. The species differs from the 

 existing A. calva, L., and its cotemporary A. reticulata, in the large size of 

 its scales, of which only seven and a half longitudinal rows are visible 

 above the vertebral column. The radii of the anal fin number nine, and 

 the caudal vertebrae forty-six; caudal hsemapophyses number twelve. 



Measurements. 



M. 



liength from first caudal vertebra to end of caudal haemapophyses 0.210 



Depth of body at anal fin 100 



Length of b.ase of anal fin. 1 028 



Length of body of a vertebra 005 



Depth of body of a vertebra 009 



The specimen of the full size of the A. calva, is from neai* Florissant, 

 South Park, Colorado. 



Amia dictyocephala Cope. 



Bulletin U. S. Geol. Surv. Terrs., 2d Series, 1875, p. 3. 

 Plate LIX; fig. 1. 



Established on a number of specimens, but primarily on one in which 

 the caudal and inferior fins are wanting, and only the posterior part of the 



