ORDER TESTACEA. 95 
tremely thin and almost equal valves, one brown, the other 
white ; and internal ribs, fine as hairs, approximated two by 
two. 
Lima, Brug. 
The lime differ from the pectens, in the superior length of 
their shell, in a direction perpendicular to the hinge, the ears 
of which are shorter, and the sides less unequal, thus forming 
an oblique oval. The ribs of most of them are raised with 
scales. The valves cannot join during the life of the animal, 
whose mantle is furnished with numberless filaments of differ- 
ent lengths, without tubercles, and more internally with a 
large border, which closes the opening of the shell, and even 
forms a veil in front; the foot is small, and the byssus trifling. 
The lime swim with rapidity, by means of their valves. 
One species, the Ostrea lima, L., Chemn. VII. lxviii. 651, 
of a fine white, inhabits the Mediterranean. It is eaten. 
PrepwuM, Brug. 
The oblong and oblique shell, with small ears of the lime ; 
but the valves are unequal, and only the most convex has a 
deep emargination for the byssus. The animal is similar to 
that of a lima, but its mantle is only furnished with a single 
range of small slender tentacula. Its byssus is larger. 
Buta single species is known ; it inhabits the Indian Ocean. 
(Ostrea spondyloidea, Gm.) 
Certain fossils may be placed here, which have the hinge, 
ligament, and central muscle of the ostrea, pectines, and 
lime, but are distinguished by some of the details of the 
shell. 
HINNITA, Defr. 
The hinnitz appear to be ostrez, or lime with small ears, 
and adhering, irregular, and very thick shells, the convex 
