JOURNAL OF CONCHOLOGY. 1 95 



DESTRUCTION OF SHELL-LIFE BY FLOODS. 

 By CHARLES ASHFORD. 



In a former volume of this journal (ii., p. 322) appeared an 

 interesting article by Mr. R. Scharff, in which he pointed out the 

 advantage to the conchologist of examining material left on the 

 banks of rivers after the subsidence of extensive floods. I can 

 speak from experience to the value of his advice. Not only can 

 we learn in a short time what species frequent the stream and its 

 banks, but we can also form a tolerable estimate of the compara- 

 tive abundance or scarcity of the different species. To those 

 whose time is limited, or who desire numerous examples of the 

 occurring kinds, the practice of bringing home, drying and 

 winnowing a bagful of the stranded rubbish cannot be too 

 strongly recommended though they miist not expect to be often 

 rewarded with so rich a "find" as fell to the lot of Mr. Scharff on 

 the banks of the Garonne. Five-and-twenty years ago I acquired 

 a very gratifying supply of V. ptisiHa, V. stihstriata and V. 

 7nhiutissivm, not to mention common species, by bringing home 

 and looking over with a feather a quantity of debris from the foot 

 of limestone rocks in Yorkshire. 



In the early part of last December my brother and I found 

 from the examination of broken reeds and grasses left in a 

 meadow by the subsidence of the R. Avon near Christchurch, 

 among several other species both from land andwater, avast number 

 of the young of Succinea putris. A few of larger growth were 

 among them, but the bulk of the considerable heap of shells 

 which remained after the winnowing, were from the preceding 

 summer's spawn. These small shells, measuring two to three 

 millimetres in length and weighing 80 to the grain, were as nearly 

 as I could judge of about a fortnight's or three weeks' growth. 



