804. 



papillae. The capillaries are connected together at the bases of the 

 secondary papillse, and arise from a common trunk immersed in the 

 body of the papilla. The nerves are found to subdivide in the se- 

 parate cones, in which they ascend to the apex and terminate in 

 abrupt extremities, as in the frog, toad, &c. In the fcetus the fun- 

 giform papillae are stated to consist of a simple cone without any 

 secondary papillae. 



3. The conical or filiform papillae of man are described to be of 

 a compound nature, consisting of numerous secondary cones spring- 

 ing from a common stem. Each of these secondary cones is clothed 

 with an elongated process which is fitted on the cone like a sheath. 

 This process consists of elongated epithelial scales ascending towards 

 the summit, and resembling in general appearance the feather of an 

 arrow. At their summit these processes are clothed with an exter- 

 nal zone of granular matter, which considerably adds to their thick- 

 ness. This granular matter is often detached after the papilla has 

 been removed a short time fr^ra the tongue. The blood-vessels form 

 a simple loop at the summit of the papilla, and the nerves are ar- 

 ranged in a similar manner. 



4. The inferior surface is described as very smooth, presenting 

 numerous follicles abundantly supplied with blood-vessels and nerves. 

 These follicles are generally of a conical shape and surrounded with 

 an arch composed of epithelial cells. The nerves may frequently be 

 detected and followed over the surface of the follicle, but their ex- 

 tremities are hidden amidst the blood-vessels. 



The author has illustrated the paper by several drawings. 



March 8, 1849. 



The MARQUIS OF NORTHAMPTON, V.P., In the Chair. 



A paper was read, entitled " Additional Observations on the Os- 

 teology of the Iguanodon and Hylaeosaurus." By Gideon Algernon 

 Mantell, Esq., LL.D., F.R.S., V.P.G.S., &c. 



This memoir is supplementary to the author's former communi- 

 cations to the Royal Society on the same subject, and comprises an 

 account of some important additions which he has lately made to 

 our previous knowledge of the osteological structure of the colossal 

 reptiles of the Wealden of the South-east of England. 



The acquisition of some gigantic and well-preserved vertebrae and 

 bones of the extremities from the Isle of Wight, and of other in- 

 structive specimens from Sussex and Surrey, induced the author to 

 resume his examination of the detached parts of the skeletons of the 

 Wealden reptiles in the British Museum, and in several private col- 

 lections ; and he states as the most important result of his investi- 

 gations, the determination of the structure of the vertebral column, 

 pectoral arch, and anterior extremities of the Iguanodon. In the la- 

 borious and difficult task of examining and compaiing the numerous 



