THE NAUTILUS. 33 



ture small, ovate, less than half the lengtii of the shell, the ends of 

 the lip approaching. Length 15, diam. 7.3, longest axis of aperture 

 6.5 mm. 



El Paso, Texas. Types no. 83259, A. N. S. P., collected by Jas. 

 H. Ferriss, 1902. 



PUBLICATIONS RECEIVED. 



The Mollusca of the Chicago Area: Part II., The Gas- 

 teropoda. By Frank Collins Baker, Chicago Academy of Sciences. 

 Bull. No. Ill, pt. II. 



This handsome volume of 288 pages and 9 plates, which completes 

 Mr. Baker's work on the Mollusca of the Chicago Area, will be a 

 most welcome addition to the library of every American concholo- 

 gist. 



It has been for years a source of regret to all students of the 

 American mollusca that so little attention has been given by our 

 leading conchologists to the study of our fresh-water species. For 

 more than thirty years practically nothing, except here and there a 

 description of some supposed new form, has been published on this 

 subject. The invaluable monographs published by the Smithsonian 

 Institute have not only been out of print and scarcely attainable for 

 years, but are quite out of date from a scientific standpoint. There 

 is at present no work which gives the results of the material which 

 has been accumulated in the public and private collections of this 

 county, since the publication of those monographs, or embodies the 

 modern ideas of classification. The land mollusks have a[)parently 

 absorbed the attention of our working conchologists and the fiuviatile 

 forms have been almost totally ignored. The recent synopsis of the 

 Naiades by Mr. Simpson has filled a long felt want, and placed that 

 group in an enviable condition. The studies of Dr. Sterki are 

 rapidly bringing the species of Sphserium and Pisidium out of their 

 chaotic condition. Similar work upon the fresh-water univalves is one 

 of the greatest needs of American Conchology to-day. Mr. Baker's 

 book is an important advance in the right direction, and should be 

 an incentive for others to undertake similar work in other states. It 

 is the first publication in this county, which attempts to treat the 

 fiuviatile forms with the same detail and thoroughness, which has 

 been given to the terrestrial species. Both the author and the 



