1908. 



W. Michaelsen : Oligochœta of the Indian Empire and Ceylon. 



117 



and Eastern x\sia towards the locality of Helodrilus japonicus, may pass not very far 

 from the locality of H. indicus. It would be desirable, however, to ascertain the 

 endemic nature of this species from Bengal, which is not beyond doubt. Indeed, it 

 might as well be a species peregrine in a small degree, imported from the proper 

 dominion of the Lumbricids, which is not far off. 



The Indiarr lyUmbricid, even if really endemic in Bengal, in no case influences 

 the faunistic character of this Indian district. It must be regarded as a settler 

 of recent geological date, and of northerly descent. 



Family MomUgastnda.e, — This family is represented by a great number of un- 

 doubtedly endemic Indian and Burmese species. The phyletic relations between 

 its four genera have been cleared beyond doubt. The most archaic genus is Desmogaster, 

 with a holoandric sexual apparatus. From Desmogaster have been derived in two 

 different ways the genera Eupolygaster and Drawida by a reduction and a disloca- 

 tion of the sexual apparatus, Eupolygaster being protandric and Drawida metandric. 

 [The fact of this reduction is confirmed by the study of the new species Drawida willsi, 

 MICHLSN., (see below) which still shows rudiments of the last anterior sexual appa- 

 ratus.] The last genus, Moniligastev , is a direct offspring of Drawida and nearly 

 allied to it. 



The ancestral genus Desmogaster is endemic in the eastern part of our region, 

 viz., in Burma, and also in the Great Sunda Islands south of it, in Sumatra and Java. 

 Just the same districts are inhabited by the endemic species of the genus Eupolygaster. 

 The other younger phyletic branch of this family, the genera Drawida and Moniligaster, 

 has a quite different habitat. The bulk of its species, indeed all the undoubtedly en- 



*i' Desmogaster 

 ^ Eupolygaster 

 OEup. doubtf. 

 • Drawida 

 O Dr. peregr. 

 or doubtf. 

 >f Moniligaster^ 



\a\ \ 



demie ones, are found in South India and Ceylon. Only a few species of these generally 

 occur outside of this district ; but there is hardly any doubt that these outsiders are 

 wanderers. This is certain as regards Drawida harwelli (BEDD.) and D. bur char di, 

 MICHLSN., and very probably as regards D. japonica (MICHLSN.) {= D. willsi, 

 MICHLSN.?) and of D. bahamensis{BVX>T>.), the Bahama Islands surely not being the 



