NOTES OX THK RELATIONS OF THE MOLLUS- 

 CAN FAUNA OF THE PERUVIAN ZOOLOG- 

 ICAL PROVJNt !E 



hi;. WILLIAM IILALl 



Having recently summarized the faunal relations exist- 

 ing between the mollusca of the deep sea, off the western 

 coast of Sonth America, and those of other regions, 1 it 

 has happened that in reporting on a collection of mollusca 

 submitted for examination by the government of Peru, it 

 fell to me to compile a census of the mollusca inhabiting 

 the shallow waters and coasts of the region known as 

 the Peruvian zoological province. Such an enumeration 

 had not been made for something like half a century. The 

 much fuller knowledge of these animals now possessed 

 by scientific students makes the number of species belong- 

 ing to this region much greater than was formerly sup- 

 posed, and modifies in consequence the conclusions for- 

 merly arrived at. 



The littoral fauna has practically nothing in common 

 with that of the abysses. The relations of the two groups 

 of animals to each other, to adjacent faunas, and to the 

 Tertiary fauna, have recently assumed a special interest, 

 from the discussions by von Ihering and others as to the 

 routes of Tertiary migrations. 



It was thought therefore that a summary of the results 

 deduced from a study of this faunal list would have a 

 certain general interest not only for malacologists but for 

 the students of historical geology. 



The littoral marine molluscan faunas of the west coast 

 of the two Americas, excluding the Arctic and Antarctic 

 faunas properlv so-called, were recognized more than 



