178 Reviews — ZitteVs Palceontologt/. 



the microscopic aspect of thin sections, giving photomicrographs 

 on pis. iv-viii. He describes the examination of the residues after 

 washing, lists the minerals found, and tabulates the results. He 

 gives a summary of the chemical analyses, and lists the Foraminifera, 

 the species of which were determined by Mr. Chapman. The 

 amount of valuable information thus brought together enables the 

 authors to discuss the " Evidence of current action at the base 

 of the Chalk," "Limits of the Chalk Sea," "Sedimentation," and 

 the "Depth of Water" beneath which the several zones were 

 accumulated. This last consideration is naturally a difficult problem, 

 and no definite statement is possible. But the general considerations 

 drawn from recent sources and the internal evidence available for 

 observation " make it probable that the Chalk marl of the south- 

 eastern and south-central counties was formed at a depth approaching, 

 but probably rather less than 400 fathoms." Quoting Dr. Hume's 

 concbisions, the authoi's continue — " it would seem that in passing 

 upwards from the Chalk marl to the beds of nearly white chalk 

 which underlie the Belemnite Marls, we are tracing the effects of 

 a subsidence which carried the area through the bathymetrical limit 

 of 400 fathoms, and that the zone of Holaster subglobosus was formed 

 in water which finally approximated to a depth of 500 fathoms." 

 Passing on to the lower beds of the White Chalk, the authors admit 

 that the difficulties are greater. "No inference as to depth can 

 be drawn from consideration of the mineral particles," beyond that 

 " it [the ' Middle ' Chalk] was formed in clear water of some depth 

 at a considerable distance from land and in a region where there 

 were no volcanoes." The evidence of the animal life seenas to be 

 conflicting, according to our present-day knowledge, and " it is very 

 probable that during part of the Middle Chalk time the depth 

 exceeded 500 fathoms ; but .... there seems to have been 

 a recovery by upheaval during the formation of the Chalk rock 

 (zone of Holaster planus), consequently the time of greatest depth 

 was probably that when tlie lower part of the Terehrutulina zone 

 was being accumulated." 



II. — GRUNDziJGE DER Palaontologie (Palaozoologie), von Karl 

 A. von Zittel, Professor an der Universitat zu Miincheu. 

 AbtheiUmg I : Invertebrata. Zweite verbesserte und vermehrte 

 Auflage. Mit 1405 in den Text gedruckten Abbildungen. 

 Miinchen und Berlin, Oldenbourg, 1903. 



Textbook of Paleontology (Paleozoology). By K. A. von 

 Zittel, Professor at the University of Munich. Part I : In- 

 vertebrata. Second edition, revised and enlai'ged, with 1405 

 figures printed in the text. 8vo ; pp. viii,558. (Price 16s. 6d.) 



THAT a second edition of a work so valuable to all students of 

 Palaeontology as the " Grundziige " of the late Professor von 

 Zittel should be called for, after the lapse of nine years since 

 the issue of the original, is not a matter of surprise. It is greatly 

 to be lamented that the author should have been snatched away by 

 his fatal malady whilst the revision was in progress, so that he was 



