STYLIFER. 



animal penetrate into the substance of the Star-fish, in 

 which it makes a comfortable cyst for itself, wherein it 

 most probably turns by the aid of- its rudimentary foot. 

 All the specimens infested with Styliferi appeared to be in 

 the best health though there is reason to believe that they 

 feed upon the juices of the Star-fish. With that instinct 

 of self-preservation imparted to all parasites, whose exis- 

 tence depends upon that of their nidus, the Stylifer, like 

 the Ichneumon among Insects, appears to avoid the vital 

 parts ; for in no instance did Mr. Cuming find it imbedded 

 anywhere, save in the rays, though some had penetrated 

 at their base and very near the pelvis. When extracted 

 the older shells have much the appearance of a milky 

 clouded glass bubble; the younger shells are of an un- 

 clouded transparency 



Dr. Turton in the second volume of the Zoological 

 Journal p. 367, plate 11, describes and figures a shell 

 under the name of Phasianella stylifera, adding that he 

 found a dozen attached to the spines of Echinus esculen- 

 tus dredged up in Torbay. It is clear that Dr. Turton's 

 shell is not a Phasianella, for it is described as having no 

 operculum and the similarity of the shell leaves no doubt, 

 when joined to the parasitic habits of the animal, that it is 

 one of the congeners of Stylifer astericola. 



Mr. Sowerby has furnished me with a third species, 

 which, although its habits are unknown to me, I consider 

 to be referrible to this Genus, and I propose to name it 

 Stylifer subulatus; it is so beautifully transparent that in 

 fine specimens the columella can be as distinctly seen as 

 if there were no intervening medium ; and its long apex, 

 which consists of many close-set whorls is generally out 

 of the perpendicular. 



W. J. BnoDERir. 



In our plate we have represented at 



Fig. 1. A portion of Asterias Solaris, showing the Stylifer Astericola in 

 i ts cyst. 



2. Stylifer Astericola, of the natural size. 



Sand 4. mag-nified. 



5. Stylifer subulatus, of the natural size. 

 6 and 7. ■■ magnified. 



8. Stylifer Astericola with its animal, dorsal aspect, magnified. 

 a. OA'al orifice of the mantle, b. generative (?) organs. 



