Vol. X, No. 10.] Indian Spiders. 419 



[N.S.] 



is doubtful, and perhaps also without a good parallel among 



the Aceraiinae. 



The evolution of the Aviculariinae is thus correlated with 

 the distribution of that subfamily in a more complex manner 

 than is that of the Aceraiinae. But, excluding groups whose 

 habits take them out of competition with the other groups of 

 their subfamily, we find in each subfamily that the evolu- 

 tionary process has progressed further in the groups centred 

 beyond the Ganges than in those centred on this side of it. 

 The correlation of evolution with distribution is quite as marked 

 among the Aviculariinae as it is among the Aceraiinae, but it 

 is somewhat obscured by the extension of the range of the 

 most highly specialized transgangetic genus Chilobrachys into 

 India and Ceylon, and by the appearance in these countries of 

 the highly specialized genus Poecilotheria with arboreal habits. 



With regard to the distribution of other Oriental Mygalo- 

 morph spiders I have nothing to say at present. Their smaller 

 average size must make aerial distribution easier among them 

 than among the Aviculariinae ; and this will presumably be 

 a factor tending to obscure very considerably any correlation 

 that might otherwise be seen between their evolution and 

 distribution. They are, moreover, very imperfectly represented 

 in the Indian Museum collection, and consequently I have 

 little personal knowledge of them. 



LIST OF LITERATURE REFERRED TO. 



1896. Thorell T. " Secondo saggio sui ragni Birmani." 



Ann. Mus Civ. Genova XXXVII (2 A, XVII) 1896-7, 



pp. 161-267. 



1897. Simon, E. " Histoire Naturelle des Araignees II, Paris, 



1897. 

 1903. Pocock, R. I. "On the Geographical Distribution of 



Spiders of the order Mygalomorphae." Proc. Zool. 



Soc." London, 1903 (I), pp. 340-368, text-figs. 58 61. 



1907. Hirst, J3. 



Ann. Mz 



text-figs. 

 1909. Hirst, S. 



en us seienocosmia. ' ' 



Hist. (7) XIX, 1907, pp. 522-4, 2 



me new or little-known Mygalomorph 



Spiders from the Oriental Region and Australia." 

 Rec. Ind. Mus. III. 1909, pp. 383-390, pi. xxiv. 



1914. Gravely, F. H. "The Evolution and Distribution 



of certain Indo- Australian Passalid Coleoptera." 

 J.A.S.B. (N. S.) X, 1914, pp. 201-210, pi. xxiv. 



1915. Gravely, F. H " Notes on Indian Spiders. I, Mygalo- 



morphae." Rec. Ind. Mus. (in the press). 



