KELLIA. 91 
have no doubt that this animal and that of K. rubra are 
furnished with these unusual appendages to minister as organs 
of reproduction. I have further to state, that on submitting 
the animal to my scalpel and one of Mr. Ross’s microscopes, 
I received the fullest confirmation of my conjectures, having 
found in the ovarium, resting on the fundus of the tube, ova 
in advanced conditions, together with fully-formed testaceous 
young. I have carefully preserved the ovarimm. Therefore 
this species, like K. rubra, is undoubtedly viviparous: the only 
difference between the two is, that one of the young phases of 
K. rubra is greatly matured in the ovary, and only requires 
the open tubular fold as an oviduct, and to convey the water 
to the pulli, which, from their position high up on the dorsal 
range, could not receive the ambient element without such an 
appendage, whilst the A. swborbicularis has the tube entire, 
as it is for some time a nidus for the young before exclusion. 
I have also to add, that on opening a very large K. sub- 
orbicularis, 1 found the contents of the ovarium converted 
from its usual ova-like aspect mto many thousands of com- 
pletely testaceous young, to be further developed before their 
issue from the anterior tube or oviduct, without which the 
water could not well be conveyed and retained for the use of 
the young. The reason why this state of the ova has so long 
escaped detection is, that the ovarium has not been examined 
at the proper season. ‘To see it as I have described, we must 
attend to the injunction of Lucretius— 
“* Atheris et terree genitabile queerere tempus.” 
K. suborbicularis, though often taken free in the muddy 
deposits of old bivalves, is also found in the crevices of the 
triassic rocks at Exmouth, in company with the Saxicave and 
Pholades, in which it rubs out a kind of cell, and thus becomes 
entitled to enter the category of the boring fraternity ; it is 
attached by a byssus,—not merely thread-like filaments, such 
as the freer ones throw out when placed in a saucer, but a 
decided membranous white hyaline byssal lamina, which 
cannot be detached without some force; it always parts from 
the animal and is left in the cell; if it is placed in water 
