1914.] J vStephenson : Oligochaeta. ^ 367 



Ceylon on the one hand as before, and on the other in the Austra- 

 lian direction to Burma and the Malay Archipelago. 



The spread of the above-mentioned genera {Plutellus, Megas- 

 colides, Notoscokx) of the Megascolecidae has been from the Austra- 

 lian region; the ancestral home of the Moniligastridae, to which 

 Drawida, so abundant in S. India, belongs, is the Further India- 

 Malayan region. The extension has thus been, in both families, 

 towards India from outside. As Michaelsen (3, 4) has made 

 abundantly clear, there must in the past have existed means of 

 communication between Australia and India, though not neces- 

 sarily by means of broad or permanent land bridges. 



The view naturally first presents itself that India has been 

 invaded by the representatives of the Megascolecidae by way of 

 the Malay Peninsula round the head of the Bay of Bengal ; and 

 by the Moniligastridae from Burma (part of their original home) in 

 the same way. Michaelsen however supposes a more direct means 

 of communication, by way of a now submerged archipelago in the 

 situation of the present Bay of Bengal (4) : — ''Die verschiedenen 

 zwischen Neuseeland, Australien, dem Malayischen Archipel und 

 Hinterindien einerseits und den verschiedenen Distrikten Vorderin- 

 diens samt Ceylon andererseits ausgespannten Landbriicken wur- 

 den gebildet durch einen Archipel (ahnlich dem Malayischen 

 Archipel) an Stelle des jetzigen Golfes von Bengalen, dessen Telle 

 ihre Gestalt und ihre Verbindungen mit einander mehrfach wech- 

 selten." To this he is led by a consideration of the close relation- 

 ship between the earthworm faunas of Australia and Ceylon, as 

 well as by the lack of endemic representatives of the Moniligas- 

 tridae in the plains of India {4) ; ''es ist zum mindesten unwahr- 

 scheinlich, dass die aus der hinterindisch-malayischen Desmogaster 

 entsprossenen Drawtda-Ahnen bei ihrer Ausbreitung nach vSiid- 

 Indien hin den in der Jetztzeit gangbaren Weg um den Golf von 

 Bengalen herum eingeschlagen haben soUten. Dieser in Siid- 

 Indien so iippig entwickelte Moniligastriden-Zweig wiirde in den 

 Zwischendistrikten, in Bengalen, Orissa. etc., wohl Relikte Zur- 

 iickgelassen haben ; denn dies sind k<2ine Distrikte, in denen beson- 

 ders kraftige Formen wie Pheretima oder Lumbricidae herrs- 

 chen. Es ist wahrscheinlich, dass den Moniligastriden ein anderer 

 Weg von Hinterindien-Malakka-Sumatra nach Siid-Indien often 

 stand, ein weg, der jetzt vom Golf von Bengalen ijberflutet 

 ist." 



The fact that Drawida is one of the characteristic genera of 

 the Abor country is therefore interesting, and may have some 

 bearing on a future discussion of this question. The present 

 records of the phyletically older genera of the Megascolecine 

 branch of the Megascolecidae may be taken along with this occur- 

 rence of Drawida. On the alternative theory (invasion of India 

 by Megascolecidae and Moniligastridae by a route round the head 

 of the Bay of Bengal), these would represent traces, not yet obli- 

 terated by rival competitors, in the march of these invading 

 genera from the south-east. 



