Mollusks, 



6541 



fish sent as having been taken out of the rain pool referred to ; they are very young 

 minnows. On reading the evidence it appears to me most probably to be only a 

 practical joke of the mates of John Lewis, who seem to have thrown a pailful of 

 water with the fish in it over him, and he appears to have returned them to the pool 

 from which they were originally taken. The fish forwarded are very unlike those taken 

 up in whirlwinds in tropical countries, and we must make allowance for unintentional 

 exaggerations of quantity, &c, in an account given a month after the event had 

 occurred.— J. E. Gray ; British Museum, April 2, 1859. 



[In a small tank in the Zoological Gardens, Regent's Park, are a few little fishes 

 purporting to be the identical specimens submitted to Professor Owen's inspection : 

 one only of these is a minnow, the rest are the smooth-tailed stickleback (Gasterosleus 

 leiurus). Dr. Gray is without doubt correct in attributing the whole affair to some 

 practical joker. — Edward Newman]. 



The Mode by which the Pholas bores. — The mode by which the Pholas bores its 

 habitation, even in the hardest rock (?), has long been a subject of ingenious speculation 

 amongst naturalists. None of their theories advanced, however, have been accepted as 

 fully satisfactory ; and no one previous to myself has had, I believe, the satisfaction of 

 seeing the animal in the operation. I have therefore great pleasure in giving a short 

 account of the manner in which I have seen the act performed. The aquarium, one 

 might have supposed, would have afforded an easy means of solving the problem. But 

 here we meet a fresh difficulty from the supposed fact that the Pholas, being once 

 dragged from its lone abode, would not take the trouble to excavate another. His 

 theory appeared to me most unnatural and improbable ; and my opinion seemed to be 

 further borne out from the fact that old logs of wood thrown up by the waves were 

 frequently covered with holes of different sizes and depths from one-eighth of an inch 

 to the entire thickness of the log. These holes appeared to me evidently made by 

 Pholades, and to have been almost immediately abandoned, either through caprice or 

 necessity. The latter we may frequently suppose to be the case ; when the log, resting 

 quietly at the bottom of the sea, is pitched upon by a houseless Pholas, and operations 

 commenced, when the ruthless storm drifts the log on shore and hurls the Pholas once 

 more at the mercy of the winds and waves. There is another case, in which the Pholas 

 may require a fresh habitation, for procuring which we should suppose Nature had 

 given it the means : it is this. Many of the logs tenanted by Pholades are so thin 

 that they would serve the growing mollusk but a short time ; and, moreover, wood and 

 other substances used by them, being of a perishable nature must render a fresh abode 

 frequently necessary. Having, therefore, procured several of these mollusks in pieces 

 of timber, I extracted one and placed it loose in my aquarium, with the vague hope 

 that it would perforate some sandstone, on which I had placed it. It possessed the 

 powers of locomotion, but made no attempt to bore. I then cut a piece of wood 

 from the timber in which it had been found, and placed the Pholas in a hole, a little 

 more than a quarter of an inch deep. Its shell being about two inches long, this 

 arrangement left about an inch and three-quarters exposed. After a short time, the 

 animal attached its foot to the bottom of the hole and commenced swaying itself from 

 side to side, until the hole was of sufficient depth to allow it to proceed in the following 

 manner. It inflated itself with water, apparently to its fullest extent, raising its shell 



