234 Reviews — N. American Echinoidea. 



Of the four concluding chapters, one gives an outline of the 

 physical history of the island from the continental conditions 

 indicated by the Scotland series till the recent elevations ; a second 

 is devoted to the general configuration and drainage, a point of 

 much interest in connexion with the recent operations of the Water 

 Supply Company, under the able guidance of Mr. E. Easton, C.E., 

 F.G.S., in intercepting the underground water-courses. The final 

 chapters are on the soils and surface deposits and contain an account 

 of the economic products of the island. 



The memoir is certainly a most valuable contribution to our 

 knowledge of the geology of the Caribbean area ; but it must be 

 judged not so much as a scientific monograph as a popular guide to 

 the authors' geological map of the island. Its treatment of the 

 scientific problems involved is only preliminary to the series of 

 more detailed papers to be published elsewhere. But the work is 

 so simply and interestingly written, and the points upon which 

 further evidence is wanted so clearly indicated, that it ought to 

 stimulate the residents of Barbados to a more careful search of the 

 lower beds, and thus enable the authors to settle more definitely 

 the age of the Scotland series, which is the most important problem 

 that still awaits solution. J. W. G. 



IX. — NoKTH^ Amektcan Cretaceous Echinoidea. 

 Note stjk quklques Echinides du Terrain cretace du Mexique. 



Par G. CoTTEAU. Bull. Soc. geol. France [3] xviii. pp. 292-99. 



PL I. II. (Paris, 1890.) 

 A Eevision of the Cretaceous Echinoidea of North America. 



By W. B. Clark. Johns Hopkins University Circulars, No. 86. 



1891. 8 pp. 

 rpHE paucity of marine Mesozoic deposits in North America is in 

 X striking contrast to the extensive development of those systems 

 in Western Europe ; hence every addition to the fauna of those 

 " ages " on the other side of the Atlantic is of great interest to 

 European geologists as supplying further material to assist in the 

 study of the evolution of the same group in the two provinces. 



The Echinoidea have been especially neglected ; hence both M. 

 Cotteau and Mr. Clark are able to make most valuable additions to 

 the North American fauna; the literature of the group moreover is 

 very scattered and most of the species have been described by men 

 who were not specialists, so that a revision of the genera was greatly 

 needed. 



In M. Cotteau's paper is given a careful description of six species 

 from Mexico ; two of these, viz. DipJopodia malhosi (Ag.) and 

 Snlenia prestensis (Gras), are characteristic of the European Aptien. 

 Three of the other species are of European genera, viz., Pseudocidaris 

 saussurei, Lor., Holecfypus castilloi, Cott., and Enallaster mexicanus, 

 Cott. ; the last two are new species ; the first was originally based 

 by M. de Loriol on spines, but the test has been described by M. 

 Cotteau. The sixth species is that described by D'Orbigny as 

 Mchinoconus (Galerites) lanieri, but for which Prof. Duncan in his 



