60 



Genus Stilifkr. {Brod.) 



Testu hyalina, turbfnata, apice spirse stilutn menliente. Apertura 

 subovataj superne acuminata. Labrum acutum, sinuatum. 



PalUum crassum, carnosum, cyathiforme, testae anfractus ultimos 

 obtegens. Proį'jsds longissima, retractilis. Tentacula rotunda, crassa, 

 subacuminata, ad basin proboscidis posita. Oculi ad basin tentacu- 

 lorum, sessiles, minimi. Branchia stirps solitaria. 



Animal marinum. 



Stilifek Astericola. Stil.testd subglobosd, diaphand, lactescente; 

 anfractibus ventricosis, longitudinaliter leviter striatis, ultimo 

 viaximo ; apicis anfractibus duobus: long. -^, lai. -rr poli. 



Hab. ad Insulas Gallapagos, Asterice solaris cutem penetrans. (Lord 

 Hood's Island.) 



The arrival in this country of the shell above recorded, with the soft 

 parts, has afForded data for a geneįic character indicating a distinct 

 family among the Fectinibranchiata, the form and dispositionof whose 

 inantle differs from that of any other genus in the ovder. This man- 

 tle(which m Stil. Astericola is of a green hue,)is thick, fleshy and cup- 

 shaped, with a small aperture at its base and a free posterior niargin, 

 enveloping the soft parts and the lašt whorls of the shell, \vhich has 

 thus somevvhat the appearance of a small acorn set in its cup. On 

 the ventral aspect of this man tie is the rudiment of a footj and from 

 the small basai aperture a retractilepro6o.sc« (which vvhen exserted is 

 as long as the whole animal) is protruded. At the base of this pro- 

 boscis are t\vo thick, round, somevvhat pointed tentacula; and at the 

 base of them are the eyes or rather ocular specks \vithout pedicles. 

 The branchia is placed on a single steni. At the base of the proboscis 

 is a spherical muscular stomach, and the intestine ascends into the 

 spire of the shell, vvhere it becomes attached to the liver, which, in 

 the present species, is of an orange colour. 



Mr. Cuming found this elegant parasite burrovved in different parts 

 of the rays of the orai disk of Aslerias solaris, Gray, where it is 

 almost hidden from sight, so deeply does the animal penetrate into 

 the substance of the Starjish, in which it makes a comfortable cyst for 

 itself, wherein it most probably turns by the aid of its rudimentary 

 foot. AU the specimens infested with Stiliferi appeared to be in the 

 best health, though there is reason to believe that these Molluscafeed 

 upon the juices of the Starjish. With that instinct of self-preservation 

 imparted to all parasites vvhose existence depends upon that of their 

 nidus, the Stilifer, likę the Ichneumon among insects, appears to avoid 

 the vital parts j 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 unclouded transparency. 



Dr. Turton, in the second volume of the ' Zoological Journal' 

 (p. 367, pi. xl.), described and figured a shell under the name of Pha- 

 sianella stylifer<i, adding that he found a dozen attached to the spines 

 of Echinus esculentus dredged up in Torbay. It is tlear that Dr. Tur- 



