VERTEBRATE PALEONTOLOGY IN 1909 675 



in question comprise the sands of Chalons-sur-Vesle and the 

 Cernay conglomerate, the lignitic clays and the Faluns of Pourcy. 

 All the remains definitely identified belong to previously known 

 species. The subject of a third paper by the same author, l.c 

 p. 366, is the Carboniferous fish-fauna of the north of France. 

 Most of the species are identical with those from other localities, 

 but a new Deltodus is named and described. 



Finally Mr. Leriche, op. cit. vol. viii. pp. 5 and 6, redescribes 

 a very large cochliodont dental plate from the Belgian Carboni- 

 ferous, which had been previously assigned to Sandalodus 

 robustus. It is, however, a true Deltodus, and appears to be 

 specifically identical with the so-called Sandalodus morrisi, of 

 the English Carboniferous, which must now be known as 

 Deltodus morrisi. 



Students of the English fossil fish-fauna will be interested in 

 a note by Dr. Smith Woodward in the Proceedings of the 

 Geological Association, vol. xxi. pp. 322 and 323, on a second 

 specimen of the ganoid Dipteronotus cy phus from the Lower 

 Keuper of Bromsgrove, Worcestershire. This genus is a 

 dapedoid near akin to Clithrolepis. Although the paper was 

 read in 1909, it was not published till the first week of 1910. 



At the close of a description of certain new types of the re- 

 markable serrated Palaeozoic fossils upon the evidence of which 

 the genera Edestus, Helicoprion, etc., have been established, 

 Dr. O. P. Hay, in a paper published in the Proceedings of 

 the U.S. National Museum, vol. xxxvii. pp. 43-61, discusses 

 the nature of those structures and their probable position in the 

 animal body. That they pertain to elasmobranch fishes is 

 admitted by all, but the idea that they are teeth, comparable 

 to those of Cestracion although situated outside the mouth, 

 is, in the author's opinion, untenable if only for the reason 

 that none of the specimens exhibit any signs of wear. It is 

 inferred that these structures were partially embedded in the 

 flesh of the fishes to which they belonged, with a considerable 

 portion exposed externally and also that they were situated in 

 the middle line of the body. 



In Dr. Hay's opinion the most probable explanation of the 

 position and function of these structures is "that some ancient 

 elasmobranchs developed in front of a median dorsal fin, or 

 in place of it, not a single spine but a succession of spines. 

 The new compressed spine, serrated in front and behind, arose 



