Reviews—Professor J. W. Gregory's Fossil Bryozoa. 321 
REVIEWS. 
I.—Cartatoctvre oF tHE Fosstr Bryozoa In THE DePARTMENT OF 
GxroLocy, British Museum (Narvurat Hisrory). THe Creraczous 
BoevozoA, Vol. Il. By J. W. Greeory, DSc, ERS, F-G-S. 
8vo; pp. xlviil, 346, 9 plates, and 75 figures in the text. London: 
printed by order of the Trustees of the Museum, 1909. 
fF\HIS volume is the third of a series by Dr. Gregory on the fossil 
Bryozoa in the National Museum at South Kensington: the first, 
comprising the forms from Jurassic strata, appeared in 1896; the second, 
published in 1899, and that now under notice contain descriptions of 
forms from Cretaceous rocks. The delay of ten years in the appearance 
of the second part of the Catalogue of Cretaceous Bryozoa has arisen 
from the retirement of Dr. Gregory from the British Museum and his 
absence from Europe for several years. In this interval the Museum 
collections have largely increased, but these later additions, with 
some special exceptions of species of systematic importance, have not 
been treated in detail in the present work, but remain over, together 
with the Cheilostomata, for description in the final volume of the 
Catalogue, which will be prepared by Mr. W. D. Lang, now in charge 
of the fossil Bryozoa in the Museum. 
At the beginning of the present volume the author contributes an 
elaborate ‘‘ Introduction to the Cretaceous Bryozoan Fauna”’, which, 
but for various obstacles, should have appeared in the previous volume. 
It is of a somewhat general character, and deals with many points of 
interest in connexion with the development of the group during this 
geological period, some of which may be mentioned. 
Yhe author is of opinion that the chief modern types of Bryozoa 
had their origin in the Cretaceous era, and that a separation line 
between the Palzobryozoa and Neobryozoa might be drawn most 
appropriately between the Jurassic and the Cretaceous. The following 
three orders of Bryozoa pass upwards from the Jurassic into the 
Cretaceous :— 
1. Trepostomata, which comprises forms with a massive zoarium 
of tubular zocecia. This order is very numerously represented in 
Paleozoic rocks, and Gregory has placed in it many Jurassic species 
and states that it is abundant in the Lower Cretaceous, but both rarer 
and smaller in the Upper, and it is continued into the Cainozoic. 
Ulrich, however, the founder of the order, holds that there is no 
evidence that the group survived later than the Paleozoic era,! and 
he relegates to the Cyclostomata many of the genera which Gregory 
has transferred to the Trepostomata. 
2. Cyclostomata. The Bryozoa of this order are very numerous, 
and they are predominant in the Cretaceous rocks; the author divides 
it into the three sub-orders of Tubulata, Dactylethrata, and Cancellata. 
3. Cheilostomata. This order makes its first appearance in the 
Jurassic, but only two species are known in this epoch; it first 
1 Zittel, Text-book of Paleontology, Kastman’s translation, p. 290. 
DECADE V.—VOL. VII.—wNO. VII. 21 
