526 dr. g. e. dobson on the [June 20, 



Dr. G until er stated that not only the living tortoises, but also 

 the shells of the specimens described in the foregoing letter, with a 

 large and highly interesting collection of other zoological objects had 

 arrived. There had not been sufficient time to examine the whole 

 of the contents ; so that a full report must be deferred to a future 

 meeting of the Society. At present he exhibited the largest of 

 several specimens of Amblyrhynchus cristatus (4| feet long), and 

 carapaces of the Abingdon and Albemarle Tortoises. The former 

 was probably identical with Testudo ephippium ; the latter came 

 nearest to Testudo elephantopus. However, the skulls had not been 

 extracted from the skins, and therefore could not yet be used hi 

 the determination of the species. Of the living examples collected by 

 Commander Cookson at Tagus Cove, Albemarle Island, four had 

 safely arrived in England, and were now living in the Gardens of the 

 Society — two large ones, a pair, brought in H.M.S. ' Peterel,' and 

 two smaller ones, probably both females, transferred by Commander 

 Cookson to H.M.S. ' Challenger,' in which ship they arrived some 

 weeks ago. None of the specimens put on board the ' Repulse ' 

 had arrived in England ; and it was reported that all had been lost 

 during a storm encountered by that ship on her voyage home. 



Dr. Guntheralso mentioned on this occasion that he was now con- 

 vinced that the two Aldabra Tortoises which were obtained last 

 year, and which, owing to the excellent arrangements made at the 

 Gardens, were doing very well, belonged to two distinct races (as pointed 

 out in the forthcoming second part of his paper on these animals), 

 viz. the male to Testudo elephantina, and the female to T. hololissa. 



The following papers were read : — 



1. On peculiar Structures in the Feet of certain Species of 

 Mammals which enable them to walk on smooth per- 

 pendicular surfaces. By G. E. Dobson., M.A., M.B., 

 F.L.S., &c. 



[Received May 26, 1876.] 

 (Plate LV.) 



The peculiar apparatus in the feet of Geckoes, by means of which 

 these animals are enabled to run about securely upon smooth perpen- 

 dicular surfaces, has often been referred to ; and every one has ob- 

 served the facility with which the common house-fly and many other 

 species of insects can walk upon the ceiling of a room ; but the oc- 

 currence of analogous climbing-organs in some species of Mammals 

 is not generally known, or, at least, has been but imperfectly de- 

 scribed in two instances only — namely, in Ilyrax, and in the very 

 remarkable species of Bat, Thyroptera tricolor, from Tropical 

 America. 



Several travellers have described the remarkable climbing-powers 

 of the species of Hyrax, some of which live in holes in trees, upon 



