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 fimdus of the tube, ova 

 in advanced conditions, together with fully-formed testaceous 

 young. I have carefully preserved the ovarium. 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 K. suborbicularis 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, I found the contents of the ovarium converted 

 from its usual ova-like aspect into 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 



" Athens et terrse genitabile quserere 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 Saxicava and 

 Pkoladts, 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 Avater 



