92 THE NAUTILUS. 



ALBINO POLYGYKA MONODON AND P. HIRSI:TA I am sending 

 the white (albino) form of Polyyijra monodon. which I have found 

 this season near Des Moines, Iowa. This while form is associated 

 with the ordinary brown ones, but I never find P. monodon near P. 

 monodon fruterntt. P. m. fruterna and P. hirsnta I find associated. 

 I also have a few white P. hirsuta. T. VAN HYNING. 



GEOGRAPHIC RANGE OF POLYGYRA TRIDENTATA DISCOIDEA IN 

 INDIANA I send you to-day specimens from Charlestown Landing 

 and Mt. Vernon of P. tridentata discoidea Pils. It seems that this 

 variety extends across the whole width of the State, for Charlestown 

 Landing is 50 miles above Louisville, Connelton, the original locality 

 of the variety, is 75 miles below, and Mt. Vernon is but a little way 

 above the Illinois line, where the Wabash river joins the Ohio. At 

 all of these places the variety occurs on the immediate banks of the 

 Ohio river, but when you go back into the country you get the 

 typical triden'atu L. E. DANIELS. 



PUBLICATIONS RECEIVED. 



PHYLOGENY OF Fuses AND ITS ALLIES. By Amadeus W. 

 Grabau (Smithsonian Miscellaneous Collection [no. 1417] part of 

 Vol. XLIV, 1904). 



This work represents a great amount of investigation and careful 

 study. A pupil of the late Professor Hyatt, the author has applied 

 the principles of development, parallelism and acceleration in de- 

 fining genetic boundaries. In this group the author considers the 

 protoconch and nepionic stages of the conch to be the most important, 

 although not always to be relied upon. Parallelism is constantly 

 cropping out, " but parallelism is no guide to affinity, and hence grave 

 mistakes in classification are made, unless this fact is borne in mind. 

 Parallelism is much more potent in the later stages of development 

 than in the earlier ones, although it is by no means unknown in 

 these latter." This and the following quotation briefly define the 

 author's views : 



" The Fusidrc as a group are highly accelerated, and near the 

 acme of development. Primitive types are uncommon, except in 

 the eocene and even there regressive species appear. The majority 

 of species have attained the acme of development for the group, many 



