Reviews — The Kent Coal-field. 567 



facies suggest to Mr. Bell a later date, somewhat nearer Miocene 

 times. 



How some of the rocks came into the area is an unsolved question, 

 as also the exact type and horizon of the flints. The age of the 

 rolled and mineralized bones, both of whales and land mammalia, 

 whether Pliocene or Miocene, is still considered doubtful, and the 

 author concludes by damning with faint praise the alleged pre-Crag 

 occurrence of Man. 



III. — A Contribution to the Knowledge of the extinct Sikenian 

 Desmostylus hespeeus, Marsh. By 0. P. Hay. Proc. U.S. 

 Nat. Mus., vol. xlix, p. 381, pis. lvi-viii. 

 fPHE remarkable Sirenian which forms the subject of this paper was 

 J_ originally described in 1888 by Marsh, who with very frag- 

 mentary material at his disposal was nevertheless able to determine 

 its affinities with accuracy, as is clearly proved by the specimen now 

 discussed. This consists of the greater part of a skull wanting 

 a portion of the snout and some other parts. Some of the peculiar 

 teeth are in situ. The skull differs from the usual Sirenian type 

 (1) in having the snout only slightly deflected and (2) in having the 

 narial opening comparatively small and far in advance of the orbits. 

 The teeth are extremely hypsodont, and are composed of rows of 

 cylindrical columns closely crowded together. Their peculiar 

 character led Yoshiwara and Iwasaki, who described a closely 

 allied but larger species from Japan, to regard the animal as 

 probably Proboscidean. The two species, Desmostylus hesperus, 

 Marsh, from the Western States of America, and D. watasei, Hay, 

 from Japan, are of Miocene age. 



IV. — The Fauna and Stratigraphy of the Kent Coal-field. 



Mil. HERBERT BOLTON has recently issued a paper on the 

 above subject (Trans. Instit. Mining Engineers, vol. xlix, 

 pp. 643-702, pis. vii-ix, 1915), which had been previously read 

 before the Manchester Geological and Mining Society. His researches 

 contain the results of an examination of a large series of Coal- 

 measure cores from the Kent Coal-field, obtained from localities lying 

 within "a triangular area, bounded by the coast-line from Dover to 

 Ramsgate on the east, by the Dover to Canterbury road on the south, 

 and by the railway line from Canterbury to Ramsgate on the north ". 

 The Carboniferous Limestone floor was reached at depths varying 

 from 3,185 feet at Bourne to 1,149 feet at Ebbsfleet, whereas the 

 Coal-measures were proved to exist in other parts of the region 

 investigated at considerable depths without striking the Carboniferous 

 Limestone, as for instance at Maydensole, where they were pierced 

 at 3,512 feet below Ordnance Datum. The author gives important 

 generalized sections of all the borings undertaken, including carefully 

 determined fossils found in each, with ample notes on the species, 

 the whole fauna being tabulated for comparison with that of the 

 Somerset and Bristol Coal-fields. He refers to a difference of opinion 

 between himself and Dr. Arber as to the presence or otherwise of 



