Reviews—Edriouasteroidea. oF 
development to permit the separation of the under layers of integu- 
ment in course of moulting, and traces of this division between the 
two layers, though sought in vain by some previous writers, have been 
found by him on the sides of the perforations. Consequently Harpes, 
Trinucleus, Dionide, and the rest, though highly specialized, are not 
essentially different from other trilobites, a view which accords with 
that expressed by Professor Swinnerton in the Groroercat Macazine 
for November, 1915. Dr. Richter also elucidates the peculiar method 
of rolling up the carapace, and believes that the backwardly directed 
horns of the head-shield served, not as ‘mud-shoes’, but as balancers 
when the animal swam; a similar balancer- function has been 
ascribed to the horns of Ceratocystis, Cothurnocystis, and Dendrocystis 
(see Grot. Mac., Sept. 19138, plate xii). 
VII.—Srvupms rn EprroasreromEa, I-IX. By F.A. Barner, M.A., 
D.Se., F.R.S., etc. 8vo; pp. 136, with 13 plates. Published by 
the author at ‘‘ Fabo”’, Marryat Road, Wimbledon, London, 8. W. 
1915. Price 10s. 6d. 
Jae highly, important work, completed in the past year, was 
begun as a series of articles in the Grotocican MaeazinE in 1898 
and continued, with intervals, until 1915, extending over seventeen 
years. In the reprinted form there will be found some valuable 
additions, and the very numerous illustrations in the text, as well as 
the thirteen beautiful plates, are all reproduced with care. To any 
student desirous to become acquainted with the morphology and 
classification of the Echinoderma the present work must form an 
essential part of his library; and as the original ‘‘Studies’’ are 
scattered through the volumes of the GrotocicaL Magazine during so 
many years, we must all feel extremely grateful for the ‘‘ Author’s 
Edition ’’, as Dr. Bather calls this volume. 
We heartily congratulate the author upon his completed work, and 
wish him many more years in which to continue his difficult but 
‘delightful studies of other sections of the Echinoderma. 
Vill.—Caratogure or Types anp Ficurep SprcIMENS oF BritIsH 
CRETACEOUS LAMELLIBRANCHIATA PRESERVED IN THE MUSEUM OF 
Pracrican Gxzotocy, Lonpon. Summary of Progress of the 
Geological Survey for 1914, Appendix II, pp. 66-79, 1915. 
R. H. A. ALLEN, F.G.S., one of the Paleontologists of the 
Geological Survey, is the compiler of this very excellent and 
nseful work. It forms the eighth of a series of similar lists which 
have been issued under the same auspices, the previous subjects 
treated being Eocene and Oligocene (1900); Pliocene, Pleistocene, 
and Devonian (1901); Phyllocarida and Paleozoic Echinodermata 
(1902); Rhetic, Lias, and Inferior Oolite Gasteropoda (1908) ; 
Great Oolite, Cornbrash, and Corallian Gasteropoda (1904); Rheetic 
and Lias Lamellibranchiata (1905); Lower, Middle, and Upper 
Oolite Lamellibranchiata (1906). These catalogues are all modelled 
on the same plan, the genus and species of each entry standing out 
clearly in a bold black type, followed by the author’s name, beneath 
