196 SMITH : ON THE GENUS ASTARTE. 



It would be unsafe to infer from this the probable time at which 

 the eggs of Siiccinea putris are hatched, for closer observation 

 showed that in nearly every case the winter epiphragm was formed, 

 and it was uncertain how long the animals had remained in a 

 dormant state. The flood, which had swept them from their 

 winter moorings on the vegetation bordering the river, occurred 

 in the last week of November. During the interval the greater 

 part of them, if not all, had fallen a prey to tiny but voracious 

 larvae, probably of the smaller coleopterous insects. This was 

 evident from the fact that nearly all the shells were neatly 

 cleared of their contents to the very apex, a minute ragged 

 fracture in the tender epiphragm showing the assailants' mode of 

 access. It would be futile to attempt to estimate in numbers the 

 enormous destruction which a few days had thus brought about 

 in the case of one single species. Our little winnpwing yielded 

 more than two thousand young shells of S. putris, and what we 

 brought away was not a thousandth part of what remained in 

 the lately flooded meadows. This heavy death-roll proves how 

 effective is one of many means by which the extension of each 

 class of creatures is kept within those limits which are implied by 

 the term "Balance of Animal Life." 



OBSERVATIONS ON THE GENUS ASTARTE, WITH A 



LIST OF THE KNOWN RECENT SPECIES. 



By EDGAR A. SMITH, F.Z.S., 



(Zoological Department, British Museum). 



This genus was characterized by James Sowerby in 18 16, in 

 his work entitled "The Mineral Conchology of Great Britain." 

 In it he describes several fossil forms, but at the same time 

 distinctly states that the living A. scotica may serve as the type of 

 the genus, and he also mentions^, danmonice as a second species. 

 These two names are now always considered synonymous with 



J.C, iii,, July, 1881 



