Ld 
186 Mr. Mowracu’s Account of some new ‘and rare 
the animal, therefore, is the only probable means of obtaining 
the shell. But what is most extraordinary, the place where 
these Lamellarie are only found (the salt rock in the estuary of 
Kingsbridge) has been a favourite place of research for a great 
many years; and yet not a single specimen was ever taken till 
the year 1809, about the latter end of which several were found 
in one day, and many others of various sizes on subsequent visits 
to the same spot. The locomotion of this species of Vermes is 
not very considerable; but it is extremely amorphous when in 
progressive motion. In a quiescent state, or when disturbed, the 
lamelle are contracted, and the inferior or sustentaculum is 
e eben by the esee | 
** Without a ‘phi Appeniitge? 
LAMELLARIA TENTACULATA. 
Tas. XII. Fig. 5, 6. 
Body sub-orbicular, depressed, convex above: the superior 
lamina is yellowish, sprinkled with bright brimstone colour, and 
marked with round pustules interspersed with a few black spots : 
in the front is a sinus: tentacula two, long and filiform, placed 
one on each side the front of the head: eyes two, black, situated . 
at the base of the tentacula on the outside, but usually concealed 
by the anterior margin of the superior lamina ; they are however 
sufficiently conspicuous on the under side of the animal by rea- 
son of the transparency of that part: the inferior lamina or 
sustentaculum is ovate, attenuated at the posterior end, project- 
ing a little beyond the shield or upper lamina, when the animal 
is in progressive motion, but which conceals the head or anterior 
. part, except about three-fourths of the tentacula. 
A variety is destitute of the black spots, and the yellow are 
more 
