Reviews — The Palceontographical Society. 
227 
known in the Mediterranean ; but in none of tbese three deposits does tbere occur 
a single species of the converse character. 
“ Simultaneously witli these features, we find a proportional increase of 
the Arctic species as we ascend through the Crag and Glacial series ; and that eveu 
in the Post-Glacial deposits no less than four out of a total of forty-nine are Arctic 
shells of the preceding Glacial Period, which have since receded from the British 
coasts. 
“ The Middle Glacial fauna Stands out in some discord with the above ; since in it 
not only do several Mediterraneau species unknown to British seas reappear, but the 
Proportion which these bear to the number of British species not knowu in the Medi- 
terranean is as eight to twenty-one, — a rauch larger proportion than exists in the 
Fluvio-marine Crag, and altogether beyond the proportions exhibited by the inter- 
vening forraations. The explanation is probably to be found in the Molluscan 
reraaius of this deposit having travelled from some distance, as mentioned in the Intro- 
duction to this Supplement, p. xxiii. Altogether this Middle Glacial assemblage is a 
very interesting one, and the raost important of any of the forraations succeeding the 
Crag. Several of the species which occur in it seem to have disappeared from 
the British coast during the earlier part of the Red Crag ; and while some of these 
are not known living, others are confined to the Mediterranean or other Southern 
waters. 
“ I have only to add that I am equally convinced with the authors of the Intro- 
duction to this work, that the Molluscan remains of the Middle Glacial Sand 
(t'ragmentary and worn as they occur in it) are not derived from any older deposir, but 
are contemporaneous with the sand which contains them.” 
4. To osteologists, and those who study the fossil dragons of the 
Wealden and Purbeck forraations, the continued labours of the inde- 
fatigable Professor Owen bring grand results in the descriptions and 
tigures of remains of Iguanodon Mantelli, I. Hoggii (?), I. Foxii, 
J/ylceocliampsa Vectiana. In the same volume the author continues 
his researches on the Mesozoic Pterosauria, describing and illus- 
trating many relics of Pterodactyles from the Gault, Hastings Beds, 
Kimmeridge Clay, Great Oolite, and the Lias. 
2. — Monographs of British Fossils, Published by the Palaeon- 
tographical Society. Yol. XXVIII. (for 1874). 4to. (London, 
1874.) 
I. This volume has fewer Monographs, or parts, than usual ; but 
one, and that fortunately a compLete work, is bulky in text and 
enriched with sixteen plates, which have an average of upwards of 
30 figures in each ! These (all drawn by G. S. Brady, and litho- 
graphed by T. West and G. West) illustrate the minute Bivalved 
Entomostraca which occur plentifully in many clays and loams of 
Post-Tertiary date, and have their analogues, and offen their exact 
representatives, in the existing seas, lakes, and rivers. The Palaeon- 
tographical Society has already published Monographs by Rupert 
Jones on the Cretaceous and Tertiary species ; and the present Mono- 
graph, by Dr. G. S. Brady, a first-rate carcinologist, with whom the 
Entomostraca are favoured pets, aided by two careful naturalists 
and geologists, Messrs. H. W. Crosskey, F.G.S., and D. Robertson, 
F.G.S., advances our knowledge of these small, but true and useful 
witnesses of past conditions, bringing them en rnpport both with 
those that are found fossil in older deposits and those now living. 
The Classification of the Ostracoda (the special group of Bivalved 
Entomostraca treated of in this Monograph), according to the shape, 
