DEPOSITS ELSEWHERE THAN IN SOUTH AFRICA. 361 



the horizon of the Nova-Scotian deposits in which the Bathygnathus 

 borealis was discovered. On this subject the experienced geologist 

 Principal Dawson, F.R.S., F.G.S., adds a note to Dr. Leidy's paper, 

 a quotation from which may not be unacceptable. " The fossil was 

 found at New London, on the northern side of the island, imbedded 

 to the depth of 9 feet in red sandstone with calcareous cement. The 

 total depth from the surface was 21 feet 9 inches ; the discovery 

 was made when digging a well. The sandstone in question belongs 

 to a formation which occupies nearly the whole of Prince-Edward 

 Island, generally dipping at a small angle to the northward. It 

 includes thin beds of coarse concretionary limestone ; and at the 

 southern side of the island, where the oldest beds of the formation 

 appear, there are beds of grey clay or soft shale, and brown and grey 

 sandstone, containing silicified trunks of coniferous trees, with in- 

 distinct vegetable impressions, perhaps Calamiles. These beds may 

 either belong to the top of the Carboniferous system or to an over- 

 lying deposit of the Permian or Triassic age ; and in either case the 

 red sandstones which conformably overlie them will be equivalent to 

 the New Red of western Nova Scotia* and Connecticut, and are 

 probably Triassic or Permian." To this note there is the following 

 rider : — " Mr. Lea states he agrees with Mr. Dawson in supposing 

 these lied Sandstones to be equivalent to those of Connecticut," &c. ; 

 and he further observes, " there are many reasons in favour of re- 

 ferring them to the superior strata of the Permian series." How- 

 soever this question, viz. as between Permian and Trias, may be 

 decided, no fact is elicited in the foregoing survey indicative of 

 a Liassic age, and the majority of instances weighs in favour 

 of a Permian period. If the affinities of the Ural and Prince- 

 Edward-Island fossils have been correctly determined, we have evi- 

 dence already of the wide geographical range (North America, 

 Europe, South Africa) over which the Peptilia distinguished by 

 certain mammalian structures extended. 



The Saurians which have been referred to the family of Thecodonts, 

 the remains of which have been obtained from the dolomitic conglo- 

 merate of Bristol, have not only the teeth implanted in distinct 

 sockets, but have crowns, conical, compressed, acuminate, with an 

 anterior and posterior finely serrated edgef . A similar type of 

 tooth ( Cladiodon) has been discovered in the red sandstone of War- 

 wickshire. These " thecodonts " may form a family in the Therio- 

 dont order, if less fragmentary evidences than we now possess do 

 not show even a closer similarity in their dentition to the type 

 genera of the Karoo beds. 



The steps leading to the above results may be summed up as 

 follows : — 



To Kutorga belongs the merit of having first pointed out and 

 figured the humeral characters which he terms " foramen condy- 

 loideum internum " and " foramen condyloideum externum," but 

 under the belief that both were mammalian characteristics. In the 



* Op. cif. p. 329. t < Odontography,' 4to, 1810, p. 206. 



