185 



ceediiigly meager, but they indicate forms wliich generally appear to he most 

 nearly related with our mud-tishes, (^Aniia,) and the gars, {Lepidosteus,) 



Professor Marsh (Proceedings of the Academy of Natural Sciences of 

 Philadelphia, 1871, p. 105) has already noticed specimens from the same 

 locality, which he refers to two species of Amia about the size of A. calva, 

 and two species of Lepidosteus about the same .size as the modern gar-pike. 



AMIA. 



Amia (Peotamia) uintaensis. 



A number of specimens, discovered by Dr. Carter on the l:)uttes about ten 

 miles from Dry Creek Canon, indicate a large fish related with the modern 

 Amia, but exhibiting sufficient peculiarity to pertain to a different genus, for 

 which the name of Protamia has been proposed. 



Figs. 1, 2, Plate XXXII, represent one of the best-preserved specimens, a 

 vertebral centrum from the fore part of the dorsal series. Its breadth is con- 

 siderably gi-eater in proportion with its length than in Amia;' it is more 

 prominent below ; has a different transverse outline; has shorter parapophyses, 

 which also spring from a higher position at the sides, and the bottom of the 

 articular cones is situated considerably above the centre. 



The centrum is nearly tour times the width and three times the height of 

 its length. It is slightly curved from side to side with the convexity directed 

 forward. It is widest at the upper third, opposite the origin of the para- 

 pophyses, and is shortest at the sides intermediately. 



The articular cones have their bottom considerably above the center, and 

 are more minutely perforate for the notochord than in Amia. 



The sides of the centrum are concave between the pi'ominent articular 

 margins, and slant in a nearly straight line to the ridges defining the narrow 

 inferior surface. The latter is concave, and the lateral ridges are obtuse, and 

 excavated in an oblong shallow fossa at their fore part. 



The upper part of the centrum is transversely convex between the jtara- 

 pophyses. The articular fossas for the contiguous neural arches, as in Amia, 

 are in the form of the figure of 8, and their internal prominent borders form 

 the lateral limits of the bottom of the neural canal. 



The parapophyses are short, stout processes projecting above the middle 

 of the centrum from its widest part, and on a line with the bottom ol tlic 

 articular cones. 

 24 G 



