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 Chrysodomine and 
Buccinidae 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 CoLorapbo. 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. 
