44 Reviews — Clement Reid's Eastbourne. 



A more serious difficulty than any mentioned by Wachsmutli and 

 Springer seems to me to lie in the existence of an anal between 

 the posterior radials of Hybocystis and Hyhocrinus (Fig. 6). These 

 primitive genera undoubtedly suggest the view that both anal x and 

 the radianal were original elements of the dorsal cup. I used once 

 to think that some such view had been maintained by Wachsmuth 

 and Springer/ but they have stoutly disowned the imputation.- On 

 that view, both anal tube and arms would be outgrowths of the 

 thecal wall, containing extensions of internal organs, and composed 

 of a dorsal or outer series of supporting plates and a ventral or 

 inner series of protecting plates. Thus the mid-rib of the anal tube 

 would still be in a general way homologous (or more definitely, 

 * serially homoplastic ') with the brachials ; and x would be the 

 serial homologue of the plate that we have been speaking of as the 

 right posterior superradial, which would really be a modified 

 brachial. The difficulties of this interpretation are obvious, but 

 perhaps not insuperable. 



On both my h^'potheses, then, x corresponds more or less to 

 a brachial, and is, as are the other anals of Inadunata, a constant 

 element, the evolution and gradual disappearance of which may be 

 traced. On the last hypothesis of Wachsmuth and Springer, x differs 

 from all the other anals in being a supplementary plate, suddenly 

 introduced, and almost as suddenly disappearing. In the absence of 

 definite pi'oof, each of my readers must decide which of the three 

 views he will adopt as a working hypothesis. F, A. Bathek. 



{To be continued.) 



II. — The Geology of the Country around Eastbourne. By 

 Clement Reid, F.L.S., F.G.S. Geological Survey Memoir. 

 8vo ; pp. iv, 15. (London, 1898. Price Qd.) 



AMONG the most useful of the Geological Survey publications 

 are the exjDlanations to accompany the various sheets of the 

 maps. In this respect the Irish Survey has set the best example, 

 and has issued a complete series of Explanatory Memoirs. Much 

 yet remains to be done in England and Wales and in Scotland to 

 bring the work similarly up to date. 



Now that the Survey in England and Wales is issuing its sheets 

 on the new series of the Ordnance Survey Map the opportunity is 

 taken of publishing short Memoirs, of which those by Mr. Reid on 

 Bognor and Bournemouth have lately been noticed. We are now 

 able to call attention to the issue of another on the Geology of 

 Eastbourne, and this deals with the Cretaceous rocks from the 

 Weald Clay to the Upper Chalk, with the Woolwich Beds and 

 London Clay of Newhaven and Seaford, and with sundry superficial 

 deposits. Illustrations of the characteristic fossils are given, and 

 there are notes on disturbances and surface-erosion, on water-supply 

 and economics. 



» " Brit. Foss. Crin. II " : Ann. Mag. Nat. Hist. (6), vol. v (April, 1890^ ; see 

 pp. 322, 324. 



^ "The Perisomic Plates" : Proc. Acad. Nat. Sci. Philadelphia, vol. for 1890, 

 Feb. 1891 ; see pp. 389, 390. • 



