70 THE NAUTILUS. 



203-298, pis. 59-88, 1918.) A valuable contribution to our 

 knowledge of the Cephalopods of that region. The material 

 studied consisted of 104 specimens, representing 9 genera and 

 13 species. On the whole the material was in good condition, 

 but the author can find little to commend the use of formalin 

 in preserving Cephalopods, unless it be for some of the more 

 delicate and transparent pelagic forms. Nine new species are 

 described and figured and two new subgeneric names are pro- 

 posed Austrossia, a subgenus of Rossia, type R. australis, and 

 Tev.thidiscus, a subgenus of Opisthoteuthis, type 0. pluto. The 

 illustrations based on the preserved specimens themselves, 

 which are apparently much contracted and distorted, often fail 

 to convey as clear an idea of the animal in life as a good draw- 

 ing. C. W. J. 



FRESH-WATER BIOLOGY. By Henry Baldwin Ward, Ph. D., 

 and George Chandler Whipple, with the collaboration of a staff 

 of specialists. Pp. viii -f 1111. New York: John Wiley and 

 Sons Inc., 1918. This work treats of all groups of fresh-water 

 plants and animals. In each group (except the Bacteria and 

 fishes) there is a comprehensive outline of the system arranged 

 in the form of a key, so that any form in hand may be run 

 down to its genus or subgenus with the least labor. Typical 

 species in each genus are described and in most cases figured. 

 The figures, of which there are 1547, appear to be admirably 

 selected, and as a rule are well engraved. The chapter on 

 mollusks, by Dr. Bryant Walker (pp. 957-1020, 144 figs.) ? 

 forms an excellent introduction to this group, as the clear defi- 

 nitions and abundant figures carry the classification to subgenera. 

 As most of the figures represent the more common forms, a 

 large number of the species most likely to be encountered can 

 be determined. The well-illustrated synopsis of Unionid groups 

 will be especially useful. There is no other publication giving 

 an up-to-date and complete classification of our fresh-water 

 mollusks, the data being scattered in many books and peri- 

 odicals. 



The chapter on Conditions of Existence, by Prof. Victor E. 

 Shelford, will be of value to collectors of fresh-water shells for 



