32 ZOOLOGICAL GEOGRAPHY. [part in. 



to the mainland. Taking the six islands which seem tolei'ably 

 explored, we find that two of the species [Dcndrceca aureola and 

 Geospiza fortis) occur in all of them ; two others {Geospiza 

 strenua and Myiarclms magnirostris) in five ; four • {Mimus 

 melanofis, Geospiza fuliginosa, G. parvula, and Caraarhynchus 

 ^'prosthemclas) in four islands ; five (Certhidea olivacea, Cactornis 

 scandens, Pyroccphalus namis), and two of the birds of prey, in 

 three islands ; nine {Certhidea fusca, Progne concolor, Geospiza 

 nebulosa, G. magnirostris, Camarhynchus psittaculus, C. variegatus, 

 C. habeli and Asio accipitrinus) in two islands ; while the remaining 

 ten species are confined to one island each. These peculiar 

 species are distributed among the islands as follows. James, 

 Charles and Abingdon islands, have 2 each ; Bindloes, Chatham, 

 and Indefatigable, 1 each. The amount of speciality of James 

 Island is perhaps only apparent, owing to our ignorance of the 

 fauna of the adjacent large Albemarle island ; the most remote 

 islands north and south, Abingdon and Charles, have no doubt 

 in reality most peculiar species, as they appear to have. The 

 scarcity of peculiar species in Chatham Island is remarkable, it 

 being large, very isolated, and the nearest to the mainland. 

 There is still room for exploration in these islands, especially in 

 Albemarle, Narborough, and Hood's islands of which we know 

 nothing. 



Reptiles. — The few reptiles found in these islands are very 

 interesting. There are two snakes, a species of the American 

 genus Hcrpetodrya^, and another which was at first thought to 

 be a Chilian species {Psammophis Te7nmincJcii), but which is 

 now considered to be distinct. Of lizards there are four at least, 

 belonging to as many genera. One is a species of Phyllodactylus, 

 a wide-spread genus of Geckotidai ; the rest belong to the 

 American family of the Iguanas, one being a species of the Neo- 

 tropical genus Leiocephalus, the other two very remarkable forms, 

 Trachycephalus and Oreocejjhalus (formerly united in the genus 

 AmUyrhynchus). The first is a land, the second a marine, lizard ; 

 both are of large size and very abundant on all the islands ; and 

 they are quite distinct from any of the very numerous genera of 

 Iguanida?, spread all over the American continent. The last 



