Reviews — Cretaceous Silicisjpongia^. 131 



distribution of some of the most important species of mammals, 

 and in several cases lie illustrates the relationships of the Pleistocene 

 forms by elaborate genealogical tables. His observations on the 

 lynx are especially interesting, for he shows that the extinct race 

 of Grimaldi is precisely intermediate between the existing northern 

 race and that still found in Spain. 



The Scheammen Collection of Cretaceous Silicispongi^ in 

 THE American Museum of Natural History. By Dr. 

 Marjorie O'Connell. Bull. American Mus. Nat. Hist., 

 vol. xK, 1919. pp. 261, with 14 plates. 



fyHE palaeontologist soon learns to divide newly pubhshed matter 

 -A- into two categories, that which gives miore trouble than the 

 information offered is worth, and that which, by saving the reader 

 trouble, aids him in acquiring the new knowledge it has to impart. 

 A glance at the work under review leaves no doubt in which category 

 it should be placed. While the amount of new information it contains 

 may not be great, it is not likely that anyone wishing to gain a 

 general knowledge of Cretaceous Sponges will consult this work in 

 vain, or, having read it, will put it down without understanding 

 how far our present knowledge of the subject goes, or without 

 knowing what works to consult for further information. 



But he will have learnt more than this. The trouble he is saved 

 is the clearing away of unnecessary obstacles to knowledge, and not 

 the trouble of taking pains. A glance at pp. 34-46 shows the ordeal 

 to be undergone before you or I can become a good disciple of 

 " Palaeospongiology " (a blessed word, but a mealy mouthful). 

 The terminology of spicules is a lacerating tangle of Amphitorns, 

 Cricamphityles, Diancistras, and such like, from which one emerges 

 only to come upon Ophirhabds (" long, smooth monaxons of 

 irregular or snake-like curvature, generally tapering towards 

 both ends "), with but a Tox (" bow-shaped spicule ") and a Labid 

 (" spicTile shaped like sugar tongs ") for self-defence — and there are 

 more than a hundred of these thorny terms. But having mastered 

 the spicular terminology and learned how to apply it — here is the 

 test of its utility — the student of fossil Sponges may feel well 

 equipped for further study, and may reasonably hope that the 

 difficulties of the future will be considerably less than those already 

 overcome. Asa student, the complex terminology of types (pp. 99- 

 "101), following closely that of Schuchert and Buckman, but 

 incidentally concerns him — this is mainly the curator's care ; 

 but he will welcome the detailed account of the European Cretaceous 

 formations and the earth history of that epoch in Europe (pp. 47- 

 97), finding here the means of correlating local terminology with 

 stratigraphical terms of wider meaning. This, with a useful 

 historical resume of work on Sponges as a group, a geographical 

 analysis of the literature .of Cretaceous Sponges, a detailed systematic 



