20 
MYA plicata. 
TAB. CCCCX1 X.—fig. 3. 
Spec. Char. Oblong, ventricose, straight, an* 
teriorly gaping, truncated ; posterior side 
very short, transversely plicated. 
About twice as wide as long, nearly cylindrical ; the 
whole surface is a little waved, but the posterior side 
near the beaks, is remarkably so. 
Found in ferruginous Sand mixed with a few 
grains of green Sand, at Sandgate near Margate, 
MYA intermedia. 
TAB. CCCCXlX.—fg. 2. 
This may possibly be a distinct species, but I am in- 
clined to represent it as a variety only, because the spe- 
cimen formerly figured, (tab. 76.) is not so perfect, and 
may have been expanded by pressure. 
Many specimens like the one before us, have been 
found in the Bognor Rocks with the external ligament 
remaining. 
It is impossible to say positively to what Genus these 
and some other fossils referred to Mya rightly belong, 
as we cannot find the inner parts of the hinges. Several 
of them resemble Leach’s Genus Thracia, in having an 
external ligament, but that Genus is included in Anatina 
among the Myaires by Lamarck, and even the Lutraria 
has a small external ligament, although they are both 
arranged in families, supposed to have only an internal 
one : thus the recent Genera do not appear to be suffi- 
ciently settled to refer the fossils to ? if even we did kno\y 
the whole of their hinges. 
