306 Professor Bayley Balfour [April 20, 



As at present known, the avifauna includes forty-three species. 

 On the shores we find gulls and herons, on the streams wild-duck and 

 plovers, the date-groves are tenanted by doves and pigeons, whilst all 

 over the island weaver-birds, chats, shrikes, sunbirds, and sparrows 

 abound. Cuckoos and falcons are occasionally met with, whilst in the 

 vicinity of habitations the scavenger-hawk of the East and a carrion 

 crow are ready to perform their offices. A few quail occur on the 

 plains. All the birds except the Passeres, PicaricEe, and Columbae, 

 are of wide distribution. The Passeres are the most numerous of all, 

 and include eight species not known from other regions, and two of 

 these belong to a new type of sparrow — Bhjnchostruthus—chsiYSkG' 

 terised by the massive form of its bill. The sunbird, as might be 

 expected, is new, and is of interest from having no metallic colouring 

 on its plumage. A small lark on the plains has a peculiar plaintive 

 note, but the song-bird of the island is a new starling, its melody 

 equalling that of a thrush. 



The snakes of the island arc very peculiar. Of the four species 

 known three are endemic, and two of them are so distinct as to 

 form new genera with Asiatic and Mediterranean alliances rather 

 than African, the fourth is the same as one brought by Tristram 

 from the shores of the Dead Sea. 



Great interest always attaches to the land and fresh-water mollusca 

 of a large and ancient island, and in this feature Socotra is not dis- 

 appointing ; for a very large proportion of the shells are endemic, 

 and of the genera to which they belong some have a very instructive 

 distribution. Thus Otopoma is restricted to the East African islands 

 and Arabia, Lithidion has the same area but extends to India, 

 Cydotopsis is represented outside Socotra only in India and the 

 Seychelles, whilst Tropidophora is known from Madagascar alone. 



In all other animal groups interesting alliances of similar nature 

 are discoverable. 



On account of our scanty knowledge of the fauna of Socotra and 

 our still slighter acquaintance with that of the adjacent mainland, it 

 is impossible to estimate the proportion of the endemic part of 

 the fauna. But what we do know shows very clearly the strong 

 African facies and relation to the faunas of the other African (East) 

 islands, and at the same time indicates the occurrence in great force of 

 Arabian and S.W. Asiatic forms as well as a clear strain of Indian 

 and Eastern resemblances. 



The vegetation of the island varies in aspect with the character of 

 the rocks. Starting from the shore one finds no representative of a 

 marine pha^nogamie vegetation, although in the stagnant brackish 

 waters at the mouths of the streams naiads occur. The coast is not 

 favourable for seaweeds, being too shingly and sandy. 



On the dry sandy plains the vegetation typical of the desert 

 regions on the mainland reigns ; small-leaved, stunted, and woody 

 bushes and herbs, often so rigid as to become spiny, or fleshy 

 plants without foliage-leaves prevail. Aromatic odours are a marked 



