FAMILY 7. PARASITICA. 173 
Pl. CCXXIV. Fig. 3. 
TuRRITELLA EXOLETA, Lamarck, Anim. sans vert., vol. vii. p. 58. 
Turbo exoletus, Linnzus. 
Pl. CCXXIV. Fig. 4. (fossil.) 
TuRRITELLA SINUOSA, Sowerby, Genera of Shells, No. 12. 
Family 7. PARASITICA. 
Animal marinum, parasiticum, pallio crasso, cyathiformi, teste anfractus 
ultimos obtegente. 
We introduce this family with the name of Parasitica for the sake of 
distinguishing the peculiar habits and organization of a group of small 
parasitical mollusks, which have been associated together by Broderip 
under the common generic title of Stylifer. They are called parasites, 
in the technical meaning of the word, because they live upon the juices 
of other invertebrated animals, Radiata, Echini, &c., being found either 
- attached to, or directly imbedded in, particular parts of them ; and their 
shells present all the transparent glassy nature of being internal. The 
Styliferi are said by Broderip to be most remarkable for the peculiar form 
and disposition of their mantle ; he describes it as being thick, very large, 
and of the shape of a cup, completely enveloping the last whorl of the 
shell ; Gray, however, in noticing this mollusk in the Zoology of Beechey’s 
Voyage, says, that that organ is the foot, although Broderip further ob- 
serves, that he has traced the rudiment of a foot upon the ventral aspect 
of the mantle: we much regret that we have not the means of deter- 
mining this question. 
The only species at present known of this curious family of mollusks 
are included in the following genus, 
STYLIFER. 
