184 Mr. MoxTAGU's Account of some new and rare 
Vermes, those with a plumous appendage on the right side, 
answering the purpose of branchiz or pulmonary organs, and 
those destitute of such an apparatus for absorbing oxygen (by 
the decomposition of the water in which they "— for recruit- 
ing vital energy. 
dn order to prevent confusion, I have suffered the animals and 
"their respective shells to bear the same trivial names, so that 
they may be readily recognised in the present system, where 
Conchology makes one of the primary divisions, and indepen- 
dently treats of the testaceous part of a large portion of Vermes. 
For the two species of Lamellaria already described I beg 
leave to refer to Bulla Haliotoidea and B. plumula in Testacea — 
Britannica, where the animals are figured: the former is of that 
division which is destitute of the — appendage; the latter 
is possessed of it. 
LAMELLARIA. 
Body formed of two fleshy lamellz ; the vitals protected by a 
convoluted shell concealed beneath the skin: foramen on the 
right side. | 
= With a plumous Appendage. 
LAMELLARIA MEMBRANACEA. 
Tas. XII. Fig. 3. 
Body sub-orbicular, greatly depressed, but convex above, and — 
‚usually scalloped or irregularly indented on the margins of both 
Jamine: the superior lamina is of a brownish colour in streaks - 
and lines, covered with larger and smaller intermediate conic 
papille : the inferior lamina extends considerably beyond the 
other, and forms a broad base or sustentaculum ; this is of a pale - 
colour, spotted with blueish gray: the head is usually concealed 
between the two lamine, but is occasionally exposed by con- 
: tracting 
