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 Mollusca’), 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 Sti/ifer. His diagnosis is as 
follows :— 
“Tentacles slender, subulate, simple. Eyes sessile at the 
cuter 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 
differs in several respects from the above description. Its tenta- 
cles are thick, cylindrical, and more or less strangulated, mstead 
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withdrawn at its death; and so far from the foot being “ rudi- 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 Hulima, 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 im 
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. Mittrez. He added nothing to our 
knowledge of the animal, but attributed a greater antiquity 
than had been supposed to the discovery of Stzlifer, in a purely 
conchological point of view, by identifying the Helix corallina of 
Chemnitz as the original species. Chemnitz says that he found 
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