260 NOTES AND COMMENTS [apkil 



be Nyctinomus plicatus. After the departure of these small bats a 

 much larger species emerged from the cave in small numbers. It was 

 then, however, too dark to see even to shoot them. During the last 

 twenty years the bats appear to have considerably diminished owing 

 to the depredations of their bird enemies, according to the lessee of the 

 caves, but more probably owing to their continual disturbance by the 

 collectors of the bats' duns;." 



Lack of Discrimination in a Mollusc. 



The Gastropod mollusc Xenopihora owes its name to its habit of 

 coating the exterior of its shell with various foreign bodies. Some 

 writers have even credited it with considerable power of discrimination 

 in the selection of suitable materials. This idea was criticised in our 

 review of Mr. Cooke's chapters on Mollusca in the " Cambridge Natural 

 History," and we find our comments amply justified by Captain 

 Anderson's observations on Xenophora. pallidula published in the 

 Report we have just quoted from. He writes : " All the examples 

 obtained by me seem to show that the sole selective ability it displays is 

 in rejecting foreign bodies that are too large for it to move easily, its 

 criterion being size and not shape or material. Xenophoras from different 

 stations are seen to be very variously ornamented, but the prevailing 

 ornament on their backs is also that suitable-sized body of which the 

 largest quantity is present in the same haul of the trawl, whether this 

 be dead shells or pieces of stone, etc. At one station off Madras, in 

 the working season of 1894, the trawl was lowered over the steamer 

 track in 107 fathoms and the Xenophoras there obtained were found 

 to be adorned with small pieces of cinders and coal. Here they had 

 merely attached to themselves the commonest convenient - sized 

 objects within their reach quite irrespective of material." 



Hermit-Crab and Sea-Anemone. 



A Government Blue-book such as this Report of the Marine Survey of 

 India is so little likely to fall into the hands of naturalists, that we 

 make no apology for giving yet another extract. This relates to a 

 hermit-crab, a species of Rarapagnrus, apparently new to the Indian 

 fauna, and its associate, a colonial sea-anemone named Epizoanthus. 



" The smallest of these Pagurids inhabited gastropod shells on the 

 backs of which were growing very small colonies of the Epizoanthus ; 

 but as the Pagurids increase in size while the size of the mollusc shell 

 remains stationary, they can insert an ever-diminishing part of their 

 abdomens in their hosts' shells ; and were it not that the Epizoanthus 



