Suhspecies of the Oenus 'R\n\\o\o\A\\x%. G57 



N, Natunas : — Rh. affiais nesites, an apparently well- 

 diflferentiated form, most closely related to Rh. a. superans 

 from Malacca. 



Anambas Islands : — Rk. nereis ; Rh. " minutas." — The 

 two species point to a connexion both with Borneo and with 

 the continent, tlie former being an offshoot of the borneensis 

 type, the latter of the minor type. 



The Indo-Malayan Subregion. — Of 69 species known, 

 26 (38 per cent.) are found in this subregion, and no less 

 than 24 * are, as species, apparently autochthonous ; of the 

 remaining two, one {Rk. affinis) is certainly, the other {Rh. 

 minor) probably, Indo-Chinese. — To form a clearer idea of 

 the affinities and probable origin of this fauna it is best, 

 however, to consider the primary groups of species repre- 

 sented within the subregion ; we then arrive at the conclusion 

 that all the species of the simplex group (seven in number; 

 see footnote) probably, in the very last instance, are 

 descendants of Austro-Malayan types; that the five species 

 of the lepidus group and the only species of the macrotis 

 group can be ultimately traced back to some part of what we 

 now call Indo-China ; whereas the eleven species of the 

 philippinensis and arcuatus groups may very likely have 

 originated from purely autochthonous types. If this be so, 

 we have as a total result 15 species which (at least as 

 " types ") can be traced back to places outside the subregion 

 as against 11 apparently purely autochthonous. 



TenasSERIM tract (including Karennee) : — Rh. Thotnasi, 

 Rh. offinis macrurus; Rh. coelophyllus. — Rh. Thomasi is a 

 very peculiar modification of the Chinese and Himalayan 

 Rouxi type ; Rh. ojjinis macrurus a local representative of a 

 Himalayan species. Rh. coelophyllus has come from the south 

 (Malay Peninsula). 



Pegu tract : — Rh. affinis tener, very closely related to the 

 Himalayan form of Rh. affinis. 



Assam tract : — Rh. subhadins, also known from Nepal. 



South China and Formosa:—/?^. Rouxi sinicus, Rh. 

 affinis himalayanus^Rh. ferrum-equimim nippon ; Rk. cornutus 

 pumilus, Rh. monoceros j Rh. lanosus ; Rh. Fearsoni chinensis. 



* Seven species of the simplex group: Rh. clebensis, borneensis, virgo, 

 malayanus, nereis, stheno, andamanensis. Five of the lepidus group : 

 Bh. refulgens, acuminatus, smnatrnnus, calypso, " miniitus.'" Six of the 

 philippinensis group : Rh. philippinensis, sedtdus, trifoliatus, solitaries, 

 luctus, geminus. live of the nrcuaius group : Rh. arcuatus, suhrufns, 

 inops, Vreaghi, coelophgllus. One of the macrotis group : Rh. hirsutu's. 

 xhm. & Mag. N. Hist. Ser. 7. lo/. xvi. 43 



