THE NAUTILUS. 59 



variation, and in the land shells; also including much valu- 

 able exotic material received in exchange. It is to be hoped 

 that this collection may be preserved intact in one of the 

 public institutions of the Pacific coast, as at present a col- 

 lection of shells worthy of the State of his adoption does not 

 exist in any university or museum west of the Rockies. 

 (Science, August 21, 1914). WM. H. DALL. 



PUBLICATIONS RECEIVED. 



A DESCRIPTIVE CATALOGUE OF THE NAIADES OB PEARLY 

 FRESH-WATER MUSSELS. By Charles Torrey Simpson. Pub- 

 lished by Bryant Walker, Detroit, Mich., pp. xi,1540. Mr. 

 Simpson's Synopsis of the Naiades, 1900, next after the 

 Observations of Lea, has done more than any other work to 

 stimulate and direct the study of fresh-water mussels. Very 

 little work had been done on our fauna for many years until 

 Simpson's investigation inspired renewed research. The 

 large mass of work which has appeared in the last few years, 

 extending the lines initiated by Simpson, is the best testi- 

 monial to the value of his Synopsis. 



After the Synopsis was launched, Mr. Simpson began the 

 more comprehensive work now before us, in which all of the 

 species are described. It was intended that all should be 

 illustrated, but this expectation could not be realized, and 

 on the removal of the author to Florida in 1902, the work 

 was laid aside. Unwilling to see the progress of Naiad study 

 delayed for want of a descriptive work fully developing 

 Simpson's system, Mr. Bryant Walker undertook the publica- 

 tion of this monumental monograph, assisting Mr. Simpson in 

 completing the descriptions of the period from 1902 to Janu- 

 ary, 1913. The labor and expense of bringing out the book 

 must have been very great, and Mr. Walker has earned the 

 gratitude of conchologists for his part in it. 



Mr. Simpson has adhered to the classification of the 

 Synopsis, with few changes, in the belief that subsequent 

 work on taxonomy and nomenclature has not yet progressed 

 far enough to warrant such a general revision as will even- 



