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Show 596 MR. F. E. BEDDARD ON THE [Dec. 6, An account of the anatomy of Clavularia viridis of Quoy and Gaimard is also given. This paper will be printed entire in the Society's ' Transactions.' The following papers were read :- 1. On the Convolutions of the Cerebral Hemispheres in certain Rodents. By F R A N K E. B E D D A R D , M.A., F.R.S., Prosector to the Society. [Received December 6,1892.] The Rodents are for the most part smooth-brained animals ; there are, however, several exceptions to the universal applicability of this statement, which have been to some extent dealt with by previous writers, including myself. The Rodent brain has not, however, been subjected to that careful study to which the Ungulate and Carnivorous brains have in the hands of Dr. Krueg and Prof. Mivart. The only paper dealing with the Rodent brain in general known to me is by Dareste (1) ; but this article does not include a full description of the convolutions in any type except in the Capybara, though incidental references are made to other types in the author's general survey of the characters of the cerebral hemispheres in the group. Having formed a collection of Rodents' brains during the last year or two from material that came to hand at the Society's Gardens, I think it will perhaps be worth while to again call the attention of anatomists and systematists to the structure of the cerebral convolutions in this group of Mammalia. I have examined specimens of the following species, the brains of which show, at any rate, traces of convolutions:- Ccelogenys paca. Dasyprocta azarce. Layostomus trichodactylus. Capromys pilorides. Hydrochcerus capybara. Hystrix cristata. Sphinyurus prehensilis. villosus. Castor canadensis. Cavia porcellus. Octodon cumminyi. Myopotamus coypu. Lepus cuniculus. Aulacodus swindernianus. Dolichotis patachonica. The last two I have lately described in papers dealing with the general anatomy of the Rodents in question (3, 4). Several of these animals have been studied by previous observers; I shall refer to them in the following descriptive part of the present paper. |