VERTEBRATE PALAEONTOLOGY IN 1910 685 



style by means of their four paddles, of which the hind pair 

 is relatively larger than in the ichthyosaurs, whereas the tail, 

 which probably carried little, if anything, in the way of a fin, 

 is proportionately reduced. Dr. Andrews has worked the 

 osteology of both groups with great care. 



Fine skeletons of plesiosaurians from the Upper Lias of 

 Holzmaden are described by Dr. E. Fraas in the Palceontographica, 

 vol. Ivii., where attention is directed to the rarity of plesiosaurian 

 remains in the German Lias as compared with what obtains 

 in the corresponding English formation. Their abundance in 

 the latter indicates that these saurians were common in the 

 Liassic seas, although they did not, in all probability, congre- 

 gate in such large shoals as the commoner ichthyosaurs. The 

 majority of the English specimens come from the Lower Lias 

 of Lyme Regis, Street, and Charmouth, an horizon represented 

 by a different type of strata at Holzmaden. Dr. Fraas refers 

 his specimens to Plesiosaurus gulielmi-imperatoris, named by Prof. 

 Dames in 1895, and to a new species of Thauinatosaurus, pro- 

 posed to be called T. victor. This reptile was about 10 feet in 

 length, with a relatively small head, short and thick neck, 

 plump body, slender and nearly equal-sized paddles, and short, 

 powerful tail. 



It may be added that to the Geological Magazine^ decade 5, 

 vol. viii. p. 1 10, Dr. Andrews has contributed a note on a mounted 

 skeleton of the small Oxfordian plesiosaurian Peloneustes 

 philarchus. 



Fossil chelonians do not loom large in the work of the 

 year ; but British palaeontologists should be interested in the 

 redetermination by Mr. D. M. S. Watson, Geol. Mag., decade 5, 

 vol. vii. p. 311, of a species from the Purbeck of Swanage 

 described by myself under the name Thalassemys riietimeyeri. 

 Mr. Watson finds that the species had a mesoplastron, and 

 is therefore a member of the Amphichelydia, referable apparentl}^ 

 to the North American Jurassic genus Glyptops. 



Several new species of American fossil terrapins — all refer- 

 able to previously known genera — are described by Mr. 

 O. P. Hay in the Proc. U.S. Nat. Mus., vol. xxxviii. pp. 307- 

 236 ; and in vol. ix. of the Bull. Soc. Acad. Boulogne-sur-Mer 

 Mr. H. E. Sauvage briefly discusses the Jurassic Chelonia of 

 the Boulonnais. 



The reptiles and amphibians of the Trias and Permian 



