﻿REPORT ON LANDSHELLS COLLECTED IN PERU IN 191 1 

 BY THE YALE EXPEDITION UNDER PROFESSOR 

 HIRAM BINGHAM, WITH DESCRIPTIONS OF A NEW 

 SUBGENUS, A NEW SPECIES, AND NEW VARIETIES 



By WILLIAM HEALEY DALL 



This expedition under the auspices of the Yale Corporation 

 reached Peru in June, 191 1, and proceeded to Cuzco. The collections 

 were made chiefly in the Urubamba Valley, a region which had been 

 visited by Angrand, and perhaps other collectors, but, of which, as 

 regards its molluscan fauna comparatively little was known. 



The region seems to possess a fauna of which the species are very 

 wide-spread, and mostly have been described from other localities. 

 A few new varieties and one new species were among the shells col- 

 lected, and the addition to our knowledge of the distribution of the 

 species is valuable. 



But the most interesting result is the discovery of a new and re- 

 markable group among the Bulimulidse, characterized by a peculiar 

 internal protective armature behind which the animal can retreat 

 when menaced by such enemies as the predaceous millipedes, which 

 are known to feed upon living pulmonate mollusks. 



This internal armature has not been previously noted, as the shells 

 are uncommon in collections and this feature can only be observed by 

 opening the whorls of the spire. 



Professor H. W. Foote, in charge of the natural history work of 

 the party collected most of the shells here enumerated. 



Professor Foote writes in regard to the situs of the shells as fol- 

 lows : 



It was the dry season and winter when I was in Peru and it seemed to be 

 a resting period for all the snails we saw. They were not moving and appeared 

 to be glued to their resting places in all cases. 



The specimens labelled " near Maras " were all found on bushes, and I 

 think thousands of them could have been obtained in a day. The region where 

 they were was somewhat dry, or at least there is a long dry season, and it 

 was above the tree line. 



The shells labelled "Santa Ana" were from the valley of the Urubamba 

 River and were rather hard to find. Most of them were fastened on the under 

 side of shelving rocks. We collected nearly all we saw, but, judging by the 

 number of dead shells, snails must be common there in the wet season. The 



Smithsonian Miscellaneous Collections, Vol. 59, No. 14 



