THE ANNALS 



AXa 



MAGAZINE OF NATURAL HISTORY. 



[THIRD SERIES.] 

 No. 83. NOVEMBER 1864. 



XXXVI. — Remarks on Stilifer, a Genus of quasiparasitic Mol- 

 lusks ; with Particulars of the European Species S. Turtoni. 

 By J. GwYN Jeffreys, F.R.S.* 



In the course of my last dredging operations on the coast of 

 Shetland, which were undertaken at the instance of the British 

 Association, I obtained two full-grown and living specimens of 

 Stilifer Turtoni, adhering to an Echinus Drobachiensis of 0. F. 

 Miiller, or E. neglectus of Lamarck. The Echinus was also 

 covered with numerous clusters of egg-shaped spawn, which 

 apparently had been deposited by one of the Stilifers. 



I will not say, as is too frequently said on such occasions, 

 that nothing or but little is known on the subject ; this is not 

 the case ; but I will endeavour to add something to our know- 

 ledge of a curious mollusk, which is especially interesting in 

 respect of its peculiar structure and habits, as well as of the 

 difficulty felt by naturalists in assigning to it a correct place in 

 the system of conchology. 



For the discovery of this mollusk science is indebted to the 

 indefatigable labours of the late Dr. Turton. In the ' Zoological 

 Journal ' for October 1825, an article by him, entitled " Descrip- 

 tion of some new British Shells," comprised one which he named 

 Phasianella stylifera, and of which he says, " We found a dozen 

 of these beautiful little shells alive, and attached to the spines 

 of the Echinus escu/entus, dredged up in Torbay." The reason 

 which he gives for placing it in Phasianella is singular. It is 

 that, in order to prevent the excessive multiplication of genera, 

 he combined with that genus many of the smaller turbinated 

 shells, such as otherwise answer to Lamarck's character, whe- 

 ther they have an operculum or not ; and such as have the mar- 



* Communicated by the Author, having been read at the Meeting of the 

 British Association at Bath, Sept. 15, 18o4. 



Ann. &; Mag. N, Hist. Ser. 3. Vol. xiv. 21 



