1875.] President's Address. 79 



with H.M.S. ' Bull-dog ' having found a similar elevation in lat. 59° 40' N. 

 and long. 29° 30' W. It makes known the probable existence of a sub- 

 oceanic ridge running N.E. and S.W. between Great Britain and Green- 

 land. 



Naturalists to the Transit-of -Venus Expeditions. — On the recommenda- 

 tion of the Council, as I stated last year, Her Majesty's Government 

 attached a Botanist (who was also Geologist), a Zoologist, and a Cave 

 Explorer to the Expeditions despatched to Eodriguez, and a Naturalist 

 to the Kerguelen expedition. These Naturalists have returned, Messrs. 

 Balfour, Gulliver, and Slater from Eodriguez, and the Bev. A. E. Eaton 

 from Kerguelen's Land, bringing collections and observations in all 

 respects justifying the objects sought, and the Council's choice of agents 

 for obtaining them. 



As regards Eodriguez, the most important result obtained (and it was 

 a very unexpected one) is that, whereas in all preceding accounts of this 

 island it has been described as consisting of a nucleus of granite with 

 flanking beds of sandstone, limestone, and other aqueous rocks, and hence 

 seemed to afford a rare example of a non-volcanic oceanic island, Mr. Bal- 

 four shows that neither granite nor sandstone there exist, and that it is 

 composed wholly of igneous rocks, with patches of coralline limestone 

 along the coast. It belongs therefore geologically as well as geographically 

 to the Mascarene group, of which it is a distant outlier, and not to the 

 Seychelles group, as had been erroneously suspected. 



The general characters of the Fauna and Elora of Eodriguez were found, 

 in accordance with its geology, to approximate very closely to those of 

 the Mauritian group, upwards of 300 miles to the westward, and not to 

 partake of the distinctive features of the Seychelles, which are Indian 

 rather than African. What differences there were from the former indi- 

 cated relationships with far distant countries, and some of them were 

 extremely curious. 



The greatest interest no doubt attaches to the extinct animals, chiefly 

 Birds and Tortoises, whose remains are found in the caves of Eodriguez, 

 and which, though extensively collected by Mr. Newton and described 

 by himself, by Dr. Giinther, M. Milne-Edwards, and other authors, 

 were still but very imperfectly known. Of Birds Mr. Slater found remains 

 of thirteen species, of which six are extinct; one is found living in Bourbon 

 alone, and one of the extinct species is new to science. Of the famous 

 Solitaire (the Eodriguez representative of the Dodo) materials for the 

 construction of a complete skeleton were obtained, together with more 

 complete specimens of other birds first described by M. Milne-Edwards 

 from a few fragments. The shells and bones of three extinct Tortoises 

 were obtained in great abundance, together with those of a large Skink, 

 said to be still living in the island, but of which no certain information 

 could be obtained. 



