324 Mr. Jeffreys on Stilifer, 



breaks up into squarish angular fragments, not crystalline, per- 

 haps horny." 



In 1850, Mr. Arthur Adams, one of the authors of a work so 

 indispensable to all students of general conchology {' The Genera 

 of Recent MoUusca '), published in the 'Voyage of the Samarang' 

 some interesting details with respect to the animal of another 

 species of Stilifer. This species he named S. astericola, erro- 

 neously supposing it to be identical with the one described by 

 Broderip ; but afterwards, finding out his mistake, he substituted 

 ovoideus as the specific name of his Stilifer. His diagnosis is as 

 follows : — 



"Tentacles slender, subulate, simple. Eyes sessile at the 

 outer bases of the tentacles. Mantle enclosed. Foot 

 linguiform, forming an elongated anterior lobe, rudimen- 

 tary behind." 



As will be presently seen, the animal of the European species 

 diflfers in several respects from the above description. Its tenta- 

 cles are thick, cylindrical, and more or less strangulated, instead 

 of " slender, subulate, simple ;" the eyes are not placed " at the 

 outer bases of the tentacles," but behind them on the neck ; the 

 mantle is always expanded over part of the shell during the 

 lifetime of the animal, and never "enclosed," nor is it even 

 withdrawn at its death ; and so far from the foot being " rudi- 

 mentary behind," it is well developed, and peculiarly constructed. 

 The animal of S. Turtoni is, besides, ciliated all over — a character 

 which distinguishes it at once from any species of Eulima, with 

 which it has been usually associated in works treating on the 

 classification of the Mollusca. Perhaps this character may have 

 been hitherto overlooked. 



Messrs. Adams, in their ' Genera,' added some further in- 

 formation as to the habits of Stilifer : — 



" These singular animals are parasitic in the skins of Star- 

 fishes, burrowing beneath the surface, and producing tumours, 

 often of a considerable size. When removed and placed in 

 water, they do not appear to possess much locomotive power, 

 but extend the tongue-shaped foot, and use it as an exploring 

 organ." 



The 'Journal de Conchyliologie ' for 1851 contains a notice 

 by M. Petit de la Saussaye of the present genus, and a descrip- 

 tion of a new species, S. Mittrei. He added nothing to our 

 knowledge of the animal, but attributed a greater antiquity 

 than had been supposed to the discovery of Stilifer, in a purely 

 conchological point of view, by identifying the Helix corallina of 

 Chemnitz as the original species. Chemnitz says that he found 



