2 0. C. Marsh on the Remains of a new Enaliosaurian, 



Since these discoveries were made, the Coal-fields of England 

 and Nova Scotia, as well as those of Ohio and Pennsylvania, 

 liave afforded additional Batrachian, or Amphibian, bones and 

 footprints, so that at the present time the prevalence of this type 

 of reptilian life during the Carboniferous period is generally ad- 

 mitted. The more recent researches of Prof Dawson in the 

 Coal formation of Nova Scotia have been rewarded by the im- 

 portant discovery of a new genus (Hylonomus) of very small 

 reptiles, which, he considers, had affinities to the Lacertians, 

 and possibly belonged to that family, rather than to the Batra- 

 chians.* 



_ The remains which form the subject of the following descrip- 

 tion are of great interest, since they indicate the existence during 

 the Palaeozoic period of a group of highly organized marine 

 reptiles of large size, which have previously been found only in 

 Secondary strata. These remains consist of two vertebrae, or 

 more strictly two centra or bodies of vertebrse ; and their ap- 

 pearance, when separated from the matrix which contained 

 them, is well represented in the first of the accompanying Plates, 

 figures 1 and 2. The vertebrae were discovered by the writer 

 in August, 1855, while examining the Coal-measures of Nova 

 Scotia m company with his friend, Mr. William E. Park, of 

 Andover, Mass. Their resemblance in form and appearance to 

 the vertebras of an Ichthyosaurus was so marked, that at the time 

 of the discovery the writer referred them to that genus, and 

 made a careful exploration in the vicinity for further remains, 

 but without success. As soon as an opportunity occurred, the 

 fossils were compared with the vertebras of Ichthyosauri from the 

 Lias, and, although some points of difference were noticed, the 

 Enaliosaurian characters seemed to be equally well marked in 

 each. Wishing to obtain, if possible, some additional remains, 

 the writer for some time deferred publishing a description of the 

 vertebrae; but a careful re-examination of the locality during 

 the past summer afforded nothing of a similar nature, and there 

 seemed to be no reason for longer delay in announcing so im- 

 portant a discovery. The remains were, accordingly, brTefly no- 

 ticed by the writer in the last number of the American Journal 

 of Science ; and, as they appeared to be generically distinct from 

 any hitherto described, he then proposed for the species the 

 name Eosaurus Acadianus^ in allusion to the early appearance 

 on the earth of this higher type of reptilian life.f 



The locality which furnished these fossils is at the South Jog- 

 gins Coal formation, in Nova Scotia, on the southern shore of 



1 Geology, page 



Geological Soa < 



