88 ; CONCHOLOGY. i 
FAMILY II. 
PuHYLLipIacEA, Six genera. “s 
1. Genus Phyllidia. Pl. IX. 
A mollusca similar to the preceding genus, without a shell, but 
its back covered with a rough or coriaceous skin. Inhabits the 
Mediterranean. Three species. 
Phyllidea varicosa. Phyllidea pustulosa. 
P. ocellata. 
2. Genus Chitonellus. Pl. TX. 
Animal. Body creeping, elongated ; middle of the back pro- 
vided its entire length with a detached, multivalve shell; the 
alternate pieces for the most part longitudinal; sides naked ; 
branchie disposed around the body ; foot cleft longitudinally by a 
deep furrow. 
Shell. Each valve with strie radiating from its apex; the 
margins serrated; the base of the last valve obtuse. The testa- 
ceous plates of this genus are never joined like those of the Chiton, 
so that the animal can move in every direction. Upon the con- 
traction of the animal after death, however, these valves become 
nearly united. Inhabits the seasof New Holland. 'T'wo species. 
Chitonellus striatus. Chitonellus larveformis. 
3. Genus Chifon. Pl. IX. 
Jmimal. Body creeping, ovate oblong, convex, round at botls 
extremities ; marginated with a coriaceous skin: the back covered 
by a longitudinal series of testaceous, transverse, imbricated, and 
moveable plates; head before, sessile, with the mouth placed below, 
destitute of tentacula or eyes; branchie placed round the body, 
under the margin of the skin; and orifice at the posterior ex- 
tremity. 
Shell. Eight imbricated valves, nearly smooth, slightly cari- 
nated, and rounded at the margins : summit more or less marked 
