O. C. Marsh on the Remains of a new Enaliosaurian. 



the Chiegnecto channel, 

 Coal-i 



have a vertical thickness of 14,570 feet, or nearly three miles; 

 and contain seventy-six distinct seams of coal, with erect trees 

 and plants at twenty-two different levels. The strata dip to the 

 south at an angle of about 25^ ; and the destructive tides of the 

 bay are constantly undermining the high cliffs, and exposing 

 for miles along the coast fresh sections, rich in fossil treasures of 

 vegetable and animal life. 



The present remains were imbedded in a stratum of argilla- 

 ceous chocolate-colored shale, which forms part of group xxvi. 

 in the elaborate section of this formation made in 1852 by Sir 

 Charles Lyell and Prof. J. W. Dawson.f The position of this 

 group is a little more than 10,000 feet above the lower limits of 

 these Coal-measures, and beneath nearly 5,000 feet of coal strata, 

 containing at least twenty separate veins of coal. It is about 

 800 feet above the locality which afforded the remains of the 

 Dendrerpeton and Hylonom^s. 



This group is sixty-six feet in thickness ; and consists of choco- 

 late and gray shales, containing ironstone nodules, and inter- 

 stratified with bands of gray sandstone, in which may occasion- 

 ally be observed ripple marks, and carbonized land plants. 

 Erect SigillaricB, often of large size, occur at one level, and erect 

 Calamites at another. Prof. Dawson considers these deposits 

 estuary or fluviatile sediments, covering flats, which were at 

 times dry, or nearly 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. 



Gfroup XXV., immediately beneath the locality of the vertebras, 

 is about twenty feet in thickness ; and consists of a series of un- 

 derclays, or fossil soils, with Stigmaria, and small seams of coal, 

 in which may be seen Sigillarioe and Lepidodendra. Two feet 

 below group xxvi. there is a stratum of bituminous limestone, 

 which contains the scales of ganoid jSshes (Pakeomscus), copro- 

 lites, bivalve shells of the genus Naiadiies, and Spirorbis carbona- 

 rius attached to plants and trunks of SigillaricB. 



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

 discovered were attached to each other, as shown in Plate I. fig- 

 ures 1 and 2. Their uniformity in size and appearance, as well 

 as their collocation when found, would indicate that they be- 

 longed to the same animal, and were contiguous in the vertebral 

 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 them, and 

 furnished the material for their mineralization. The posterior 



