LONDON Geological Society, February 6.—Prof. P. M. Duncan, F.R.S., president, in the chair.—James Adey Birds, Rev. George E. Comerford-Casey, M.A., Lieut.—Col. H. H. Godwin-Austen, Sir Willoughby Jones, Bart., and Henry Richard Ladell, M.A., were elected Fellows of the Society.—The following communications were read:-On some foraminifera from pleistocene beds in Ischia, by M. Ernest Vanden Brocck. Preceded by some geological remarks by A. W. Waters, F.G.S.—On the influence of the advent of a higher form of life in modifying the structure of an older and lower form, by Prof. Owen, C.B., F.R.S. In this paper the author, after referring to the general question of the modification of the structure of organic forms produced by the action of external influences, indicated that, in connection with this, changes in the nature of the prey of carnivorous animals ought to be taken into consideration. He inferred that coldblooded aquatic animals formed a much greater proportion of the food of mesozoic than of neozoic crocodiles, and pointed out as connected therewith the well-marked distinction between the amphiccelian and proccclian type of vertebræ respectively characteristic of the two groups. The proccelian character of the trunk-vertebra; better adapts that part of the body to be sustained and moved in air, and may be connected with the incoming in tertiary times of mammalian prey inducing the crocodiles to rush on shore. The mesozoic crocodiles were encased in a much stronger and more complete dermal armour than their successors, doubtless for their protection from the great ichthyosaurs, pliosaurs, & c., which co-existed with them; but as these passed away at the close of the secondary epoch, the armour of the proccelian crocodiles has become more scanty, and the diminution of weight and rigidity thus caused would favour progression in air, and the rapidity of movement required for capturing mammalian prey on land. The difference in the position of the palato-nares, and in other related gular and palatal structures, between the mesozoic and neozoic crocodiles is apparently connected with the power possessed by the latter of holding submerged a powerful mammal without permitting the access of water to the posterior nostrils and windpipe of the crocodile; and hence the author is inclined to ascribe a fish-diet even to those massive-jawed crocodiles from the Purbeck (such as Geniopholis crassidens and simus), which in some respects might seem fitted to grapple with large and active mammals. The small size of the upper temporal apertures in tertiary and existing"crocodiles is regarded by the author as a further proof in the same direction; these apertures are reduced -by the progressive increase of the osseous roof of the temporal vacuities, which again is correlated with increase in the bulk and power of the temporal muscles, the main agents in biting and holding. The differences in the length and strength of the jaw, as a rule, testify in the same direction. Further, the fore limbs in mesozoic crocodiles are shorter than in neozoic species, indicating that the former were more strictly aquatic in their habits; the forelimbs in all crocodiles being closely applied to the body during rapid swimming, and small limbs being less obstructive than larger ones. On the other hand, they would be less efficient as a means of progression on land, and hence it may be inferred that the advent in tertiary times of mammals frequenting the water-side, templing the crocodiles to make a rush upon the land to seize such passing prey, would lead to such strenuous action of the fore-limbs as would account for the increased size and power of those organs in the neozoic species. The author concluded with some remarks upon the influence of the above considerations upon our views as to the generic divisions of crocodiles.—Notes on a supposed crocodilian jaw from the coral rag of Weymouth, by E. Tully Newton, F.G.S., of H.M. Geological Survey. In this paper the author describes what he believes to be a fragment of a lower jaw of a crocodilian, obtained from a greyish brown sandy grit, probably belonging to bed 3 of Messrs. Blake and Hudleston's Sandford-Castle section. -Note on two skulls from the Wealdeu and. Purbeck formations indicating a new sub-group of crocodilia, by J. W. Hulke, F.R.S., F.G.S. The author described a crocodilian skull obtained by Mr. H. Willett, F.G.S., from the Hastings sands near Cuckfield, in Sussex, and identified by that gentleman with Goniopholis crassidens, Owen; and another from the Purbeeks near Swanage, in the collection of the British Museum, which he 'further compared with a third specimen from Brook,:_in the Isle of Wight.