PULLASTRA. 12] 
usual thick fleshy linguiform foot, very moderately geniculated, 
and capable of all the phases from obtuse to pointed; it is 
pure white, and has not the byssal groove of the tribe, which 
is a considerable variation of structure, and the teeth are not 
so slender, long, or parallel, more resembling those of Venus, 
from which this animal scarcely differs. The mantle pos- 
teriorly forms the siphons, which are soldered together three 
parts of their length, becoming separated for the remaining 
portion; the colour is delicate pale lemon, tinged with red- 
brown at the bifurcation; they are of the same size, the 
branchial being truncate at the extremity, and clothed with 
fourteen pointed cirrhi, whereof seven are rather the largest, 
marked at their bases on each side with a patch of bistre, the 
interstitial ones are white; the anal tube curves upwards as 
in its congeners, and does not appear truncate, in consequence 
of its edges being a little inflexed; it has sixteen short white 
cirrhi at the orifice, which has also around it a dirty red-brown 
fine line ; the tubes, when fully extended, are less long than in 
the two preceding species ; they do not, as in Venus, measure 
more than half the transverse measure of the shell. The pair 
of subeireular branchize on each side are pale drab, hung very 
obliquely; the under ones are at least double the size of the 
upper, and strongly marked by the transverse vessels of the 
circulation; the palpi are subtriangular, short, and well striated. 
The liver appears scanty and of a pale green. 
This species inhabits the coralline zone at Exmouth, but is 
rarely taken alive ; dead shells in good condition are frequent. 
We almost think that this species and its variety the P. Sar- 
niensis should, from the absence of the byssal groove and the 
greater divergence of the teeth from the type, be transferred 
to the Veneres. The P. aurea has not occurred alive; is it 
distinct from the present species? the teeth of the two are of 
similar character, and if it is without the byssal groove, it 
would appear that it ought to accompany the P. virginea to 
the typical Veneres. 
