On some Nevj Marine Mollusca. 55 



the air bubble observed with a lens is seen to be in con- 

 tinual oscillation ; but simplicity, portability, and some 

 other desirable properties, seem to be sacrificed for the sake 

 of sensitiveness in this instrument; although, on the other 

 hand, it should be added that if for the first time the prin- 

 ciples involved in the aneroid form of barometer were pre- 

 sented to the mind, the carrying them into practice for 

 constructing a truly serviceable barometer would seem 

 almost beyond hope ; while experience has taught us that 

 this form of barometer, even as small as a lady's Geneva 

 watch, can be produced at relatively small cost with cer- 

 tainty and in endless quantity ; and that the aneroid 

 barometer is assisting in a large amount of valuable 

 climatic and hypsometrical observation. 



Art. IX. — On some Neiv Marine Mollusca. 



By Rev. J. E. Tennison- Woods, F.G.S., F.L.S., Hon. Memb. 

 Roy. Soc. N.S.W., Corr. Memb. Roy. Soc. Victoria, 

 Tasmania, and Phil. Soc, Linn. Soc. N.S.W., &c. 



[Read 9th August, 1877.] 



The following shells were placed at my disposal for descrip- 

 tion by Prof M'Coy, of the National Museum of Victoria. 

 I had been engaged for some time previously, preparing a 

 census of the Tasmanian marine molluscan fauna, and on 

 completing my lists and making the necessary comparisons 

 at the National Museum I came across several in the exten- 

 sive collections there which appeared to be new and 

 undescribed. Permission to describe them was very cheer- 

 fully accorded by the learned Professor, whose obliging 

 courtesy to me on all occasions where he could forward my 

 small eflforts in the interests of science I take this oppor- 

 tunity thankfully to acknowledge. It will be seen that 

 the fauna here described is not in any way divergent from 

 the recognised forms. A Birostra is, however, quite a 

 novelty in Australian seas. Amongst all the species there 

 is not one which even approximates to the extinct fauna 

 of our tertiary beds, except in the case of the Lhnopsis just 

 mentioned. N.B.— All measurements in French millimetres. 



