The President's Address. 75 



mistake in Dr. Eansom's method of procedure, as ammonia 

 does not exert the action he supposed. 



In May, Mr. E. E-ay Lankester contributed a paper on 

 " The Structure of the Tooth of Ziphius Sowerbiensis," and 

 in November Mr. Edwin T. Newton brought before us 

 certain " Anatomical Differences observed in some Species of 

 the Helices and the Limaces," the difference being " in 

 the reproductive organs, where some of the parts become 

 modified or suppressed ; in certain additions to the ali- 

 mentary canal ; and in the variations which the muscles 

 undergo. 



In December, Mr. C. Stewart brought under our notice 

 the "Structure of the Pedicellariae of the Cidaridae," and on 

 January 7th Prof. T. Rupert Jones, F.G.S., gave us an 

 account of '' Fossil Bivalved Entomostraca," showing their 

 extensive range of distribution in geologic times. 



In this last paper allusion was first made to the great 

 abundance of Entomostraca recognisable in the fossil state in 

 clays, marble, freestones, chalk, &c., as having left their 

 shells and cases in the sediments of seas, lakes, and rivers of 

 all geologic dates, just as at the present day we find the 

 living species swimming in the water, crawling on the sands, 

 or burrowing in the mud. 



Prof Rupert Jones explained the general nature, structure, 

 and habits of the Entomostraca, and of the bivalved forms 

 in particular, pointing out their relations to other Crusta- 

 ceans. He also gave an account of their distribution in 

 various rocks, from the Silurian to the Post-pleioccne, for 

 the details of which I must refer to his paper. 



Only one paper during the session referred to Entomology, 

 which was read in June by Professor Rymer Jones, F.R.S. The 

 subject was " The Structure and Metamorphosis of the Larva 

 of Coreihra Phimicornis," one of the most elegant inhabitants 

 of fresh water ponds. The anatomical details in this paper 

 will be found of much interest, and the description it gives 

 of the bursting of the four remarkable air sacs with which 

 this creature is provided, followed by the rapid appearance 

 of a tracheal system, suggests very interesting inquiries, 

 which it is hoped Fellows of this Society will undertake. 

 It cannot be supposed that an elaborate tracheal system is 

 made of a sudden ; and it does not appear that either Pro- 

 fessor Rymer Jones or any other observer has hitherto suc- 

 ceeded in tracing the usual process of development. 



In November Mr. John Gorham read the only truly 

 botanical paper of the session, on a " Peculiar Distribution 

 of the Veins in Leaves of the Umbelliferse." Mr. Gorham 



