TURTONTA. 97 
TURTONIA, Hanley. 
T. minuta, O. Fabricius. 
T. minuta, Brit. Moll. 11. p. 81, pl. 18. f.7 & 7a; (animal) pl. O. f. 1. 
Mya purpurea, Montagu et Auctorum. 
I have never seen this animal, and can only record the 
slight notes of authors, that the foot is very large, strong, 
geniculated, and issues from the shorter end of the shell; the 
mantle is largely open anteriorly, and a slender somewhat 
produced siphonal tube proceeds from the longer side. The 
shell, except in contour, in many respects agrees with the 
Lucine. The ligament is external, and there are in perfect 
specimens two cardinal teeth? in each valve, one or both is 
often bifid; the teeth vary much from being deeply cloven ; 
and thus in some examples the appearance of two, three, or 
four is presented, and in old shells they are otherwise con- 
fused and indistinct. The pallial impression is entire; the 
anterior adductor cicatrix, as in many of the Lucine, is rather 
more extended and at a lower level, but not much more, than 
the posterior one. Under the microscope we discover traces 
of the vertical lines so conspicuous in the margin of Lucina 
borealis ; and we may also state, it is thickened, dull, and 
somewhat chalky in some specimens. The slender tube also 
allies it with that section of the Lucine which have a produced 
anal conduit. 
The foot, when exserted, has the ordinary tongue-shaped 
aspect of most of the minuter bivalves, but that is no proof 
that it has not the singular tubular structure characteristic of 
the Lucine, as even in the type L. borealis and in L. rotun- 
data, both of which beyond doubt have the true Lucinidan foot, 
it shows no trace of the simgularity when protruded, probably 
from being inflated with water to produce tension, It is only 
when the animal is killed and opened that the curious con- 
figuration of the pedal organ is seen. We do not mean to say 
that Turtonia is a true Lucina, or even one at all, but merely 
mention these facts, which may have the value they deserve, 
But we will endeavour to obtain this animal. All these con- 
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