Royal Society. 225 



day. The negroes use them to wattle the walls of their huts, and 

 call the bush " Alligator Tree," probably from the two Spanish words 

 "a ligar," to tie with. Where it stands free, it attains the size of 

 a full-grown apple-tree ; but it invariably, I believe, grows within 

 shelter of some other and larger one. 



Except this genus and Trichilia, I found no other in Jamaica that 

 had the character of leaf above described. 



The President exhibited numerous specimens of recent and fossil 

 CycadeeB. Among these was a fine specimen of a new species (Cy- 

 cadites Saxbyanus, R. Br.) found in the Isle of Wight by Mr. Saxby 

 of Bonchurch. The President remarked that all the specimens of 

 Cycadites hitherto found in the Isle of Wight agreed in having an 

 elliptical outline, unaccompanied with any inequality in the woody 

 ellipsis, and also in having a bud in the axilla of each leaf ; in these 

 respects differing from the Cycadites of the Isle of Portland and from 

 all the recent species of Cycadeec with which we are acquainted, which 

 liave a circular outline and only scattered buds. 



ROYAL SOCIETY. 



Alarch 4, 1852. — A paper was read, entitled, " On the Anatomy 

 of Doris." By Albany Hancock, Esq., and Dennis Embleton, M.D., 

 Lecturer on Anatomy and Physiology in the Newcastle-on-Tyne 

 College of Medicine, in connection with the University of Durham. 

 Communicated by Professor E. Forbes, F.R.S. 



The authors have proposed to themselves to describe the anatomy 

 of the three genera typical of the three groups of the Nudibranchiate 

 MoUusca. An account of the structure of Eolis has already appeared 

 in the ' Annals of Natural History.' 



A detailed description is given of the anatomy of Doris, the fol- 

 lowing species of which have been examined, and are referred to in 

 the paper: D. tuberculata, And. , D. tuberculata.'V erany , D.Johnstoni, 

 D. tomentosa, D. repunda, D. coccinea, D. verrucosa, D. pilosa, 

 D. bilamellata, D. aspera, and D. depressa ; but D. tuberculota of 

 English authors has been taken as the type of the genus, and the 

 standard of comparison for the rest. 



Digestive System. — The mouth in all the species is a powerful 

 muscular organ, provided with a prehensile tongue beset with siliceous 

 S])ines, which when the tongue is fully developed, are arranged in a 

 median and two- lateral series. Certain species possess, besides, a 

 prehensile spinous collar on the buccal lip, occasionally associated 

 with a rudimentary horny jaw. The mode of development of the 

 lingual spines is shown to be the same as that of the teeth of the 

 Vertebra ta. 



The oesophagus varies in length ; in some it is dilated at the top, 

 forming a crop ; in others it is simply enlarged previously to enter- 

 ing the liver mass. The stomach is of two forms ; one, as in D. tuber- 

 culata, is very large, receiving the oesophagus behind, and giving off 

 ihe intestine in front, and lying in advance of the liver ; the other is 



Ann. ^ Mag. N. Hist. Scr. 2. Vol. x. 15 



