208 Marsh, description oj a new Enaliosaurian 



ly so, and at others inundated. On one of the rippled sandstones 

 he noticed a series of footprints, which he supposes might have 

 been made by a large Dendrerpeton. 



Group XXV., immediately beneath the locality of the vertebrae 

 is ab'tut twenty feet in thickness; and consists of a series of un- 

 derclays, or fossil soils, with S ti(/maria, Siud small seams of coal, in 

 which may be seen Sigillorim jmd Lepidodendra. Two feet below 

 group XXVI. there is a stratum of bituminous limestone, which 

 contains the scales of ganoid fishes (^Palceoniscus), coproiites, bi- 

 valve shells of the genus Naiadites and Spirorbis carhonarius at- 

 tached to plants and trunks of Sigillarioe. 



The vertebrae, as already stated, are two in number : and when 

 discovered were attached to each other. Their uniformity in size 

 and appearance, as well as their collocation when found, would in- 

 dicate that they belonged to the same animal, and were contiguous 

 in the vertebra! column. They are remarkably well preserved ; and 

 this results from their complete ossification in their natural state, as 

 well as from the peculiar matrix which has since contained ihem? 

 and furnished the material for their mineralization. The posterior 

 vertebra, in fact, with the exception of a small fracture, seems to 

 be nearly as perfect as in its original condition ; and from it the 

 description and measurements which follow are mainly tak'^n. 



k close examination of the fossils shows, that subsequent to the 

 death of the animal, and before being imbeded in the shale, they 

 were subjected to considerable violence. One of them has been 

 pushed aside from its original position about one-third of its di- 

 ameter, and also turned on its axis about 90°, so as to leave its 

 superior surface in apposition with the lateral surface of its fellow. 

 Through the center of the anterior vertebra an irregular cavity has 

 been made, and a wide fissure separates a segment from the rest of 

 the centrum. The edges of each of the fossils are somewhat 

 abraded, apparently from having been rolled about by water: 

 this, however, could not have been long continued ; as the 

 delicate reticulate texture of the non-articular surfaces, being 

 protected by their slight concavity, is perfectly preserved These 

 injuries were evidently received before the entombment of 

 the vertebrae ; and, as no similar remains could be found in the 

 vicinity when these were discovered, it is quite probable that the 

 same force, which caused tlie injuries, also widely separated the 

 different parts of the skeleton. 



