250 



THE EXTINCT HATKACIIIA, KEPTILIA 



The following section of tlic exposure at Pea .Shore, will give the best idea of its 

 character. 



Fis 



A The regularity of the beds as exposed for some 

 distance along the line of the Camden and Amboy 

 P. P., and their S. E. dip, apparently similar to 

 that of the Cretaceous beds above them, has seemed 

 to confirm the supposition of authors as to their 

 horizon. I believe, however, that they really be- 

 long to a much later age than the bed No. 1, and 

 are really of a Pliocene period, and older than the 

 stratified drift. Two reasons have a strong bearing 

 on the question. A large part of the cranium of 

 a horse — Equus fratcrnus of Lcidy — was found by 

 the workmen just above the Unio bed, and twenty 

 feet below the top of the clay, evidently in place. 

 The underlying bed of coarse red sand, is in all 

 apparent respects identical with the material of a 

 stratum which underlies the soil over the country 

 5 and 6 miles to the eastward of Pea Shore, e. g., 

 the town of Haddonficld, which rests unconform- 

 ably on the Ripley division of the Cretaceous. 

 1 1 does not exist on the surface, so far as I could 

 ascertain from an examination on one line, between 

 these points. It may be the same bed. 



That this bed is synchronous with our Post- 

 pliocene, is doubtful, from the marked difference 

 presented by the Unios, when compared with 

 those now existing. The Helices of the Post- 

 pliocene are identical with the living species, viz: 

 H. major, II. tridentata, II. dentifera, etc, are 

 associated with Tapirus, Dicotyles, Equus, etc;., 

 in cave deposits. The Unionidse, Tea remarks, 

 have the heavy teeth of one type of the genus, 

 w with the light thin shells of another type, and are 

 all distinct from the living. An older age than 

 Postpliocene is, therefore, indicated. 



