144 THE NAUTILUS. 



chologists, and indeed by all who are interested in American 

 marine shells. There are no descriptions, but a reference is 

 given to description and figure, if published. A large propor- 

 tion of the descriptions have appeared in the widely-distributed 

 Proceedings of the National Museum, and so are generally ac- 

 cessible to those concerned. 



A great number of moderately large and striking shells are 

 recorded from Bering Sea. The array of Chrysodominse and 

 Bucdnidae is astonishing, and so far as I know unparalleled 

 anywhere else in the world. 



The Californian fauna comprises 996 of the 2122 species 

 enumerated. 151 species are exclusively abyssal, and 136 

 species are common to the Atlantic, nearly all belonging to the 

 Arctic seas. 



In the list Dr. Dall has frequently used subgeneric names in 

 place of generic. It appears to the writer that since a binomial 

 name is defined as consisting of the generic combined with the 

 specific name, it would be better to conform to the ordinary 

 usage. The distinction between genus and subgenus is of course 

 largely a matter of individual opinion or of current use, but one 

 cannot logically consider a given group to belong to both taxo- 

 nomic grades. In more important matters there appears little 

 to criticize and much to commend and admire. 



When Dr. Dall took up the study of West Coast mollusks 

 some 468 species had been recorded. The enormous advance 

 he has made in all branches of the science, with the help of 

 many zealous workers on the coast, is shown by this volume. 

 It is a splendid record of the achievements of a generation of 

 conchologists, and an inspiration for those to come. H. A. P. 



THE CRETACEOUS FORMATIONS OF NORTHEASTERN COLORADO, 

 AND THE FOOTHILLS FORMATIONS OF CENTRAL COLORADO. Colo. 

 Geol. Surv. Bull. 19. By Junius Henderson. While con- 

 cerned mainly with Mesozoic geology and paleontology, there are 

 some references to recent mollusks, as on p. 45 where the shells 

 of Greasewood Lake, near Osgood, and of some similar eph- 

 emeral lakes are discussed. H. A. P. 



