NOTE ON SOME POST-PLIOCENE MOLLUSCS FROM THE BYCULLA FLATS. 185 



Natural History Society in the section of " Other inveriehratcC in the 

 hope that some one may be found more competent than myself to 

 discuss their characteristics. 



It seems to me such a discussion might he specially profitable in 

 two ways. First, a careful comparison of these sub-fossil shells of the 

 Byculla Flats with those at present inhabiting the sea outside, with 

 a view to determining such slight differences as may have become 

 permanent during recent geological ages, might throw much light on 

 the theory of evolution and the origin of species ; and secondly, from 

 a study of these marine remains on dry land, we may learn so much of 

 like creatures still inhabiting the sea as to be enabled more easily to 

 find living specimens of species hitherto considered rare from 

 their inaccessibility. It is chiefly in regard to the latter consideration 

 that I propose to offer a few remarks now on these fragments of 

 tubular shells which I have produced for your inspection here 

 to-day. 



Among the commonest of the shells scattered over the Byculla 

 Flats are some not unlike pieces of the broken stem of a clay 

 tobacco-pipe. My attention was first directed to them about two 

 years ago by Major E. T. Frere, R.E., who believed them to be the 

 tubes of some boring mollusc. Unfortunately he was compelled by 

 ill-health to go to England before he had prosecuted his researches 

 very far. He took with him however some specimens he had found, 

 and later I sent him some I found after his departure. By compar- 

 ing these with specimens in the collections of the British Museum 

 and the Royal College of Surgeons, and by the help of information 

 and assistance courteously afforded him by the officials at these two 

 institutions, and particularly by Mr. Etheridge, the head of the 

 Palasontological Department at the British Museum, he collected 

 some interesting information regarding the natural history of tube- 

 forming animals. This he has kindly imparted to me, and I beg to Jay 

 before the Society such portions of it as seem to bear upon the 

 specimens which I have collected from the Byculla Flats. 



When found in their least altered condition, the tubes are appa«« 

 rently calcareous and nearly white in colour, or faintly tinged 

 with pink. They vary considerably in size. But I have found no 

 fragments larger than those in the group marked No. 3 either in 

 point of length or circumference. I think the reason of this is that 

 the creatures inhabiting these shells used to bore downwards into the 

 soft oozy bottom of the lagoon I have described, big end first. The 



