1908.] W. MiCHAEi^SEN : OligochcBta of the Indian Empire and Ceylon. iig 



genera of this phyletically older part of the Megascolecine branch have in spreading 

 reached the Indo-Burmese region. The genus Plutellus has five species in Ceylon, 

 South India and the Eastern Himalayas ; in another direction it went as far as 

 North America ; it is absent in the direction towards New Zealand. The genus 

 Megascolides is represented by a single outpost in the Eastern Himalayas ; in another 

 direction it went as far as North America, while in a third it occupied the North 

 Island of New Zealand. Diporochceta is in our region probably represented by one 

 species {D. pellucida of BOURNE probably from India) ; in another direction it 

 spread over New Zealand and the Chatham Islands. The genus Spenceriella 

 also has only one species in our region, in South India, and is, in the direction of 

 New Zealand, distributed as far as I^ittle Barrier Island near the North Island. 

 Woodwardia reaches with two species (one in Ceylon, the other in Burma) into our 

 region, and is for the rest restricted to Australia. The large genus Notoscolex, 

 which otherwise, like the foregoing, is restricted to Australia, is represented by a 

 great number of species in our region, by no less than eight in Ceylon and by a 

 ninth in South India. The genus Megascolex shows a similar geographical 

 relation and is represented by nineteen species in Ceylon and by two (three ?, the 

 doubtful M. imperatrix of BOURNE) in South India. Megascolex is on the 

 other hand not totally restricted to Australia, one species being found on 

 Norfolk Island, east of Australia. The nearly allied genera Perionychella and 

 Perionyx have their headquarters in the Indo-Burmese region, Perionychella occurring 

 with five or six species in the Himalayas (one in Bengal ?), Perionyx with four endemic 

 species in Burma, the Eastern Himalayas, South India and Ceylon. Perionyx is res- 

 tricted to this region ; the phyletically older Perionychella has four species in Australia. 

 The genus Lampito, closely allied to Perionychella, is restricted, like Perionyx, to our 

 region, the only two endemic species occurring in South India. A quite different dis- 

 tribution is shown by the phyletically youngest genus of the M egascolecince , namely, 

 Pheretima, which is derived from Megascolex. The headquarters of Pheretima is the 

 Malayan Archipelago. It is distributed thence eastwards as far as the Solomon Islands 

 (or as far as the New Hebrides, or Samoa, or Tahiti?), northwards as far as 

 Japan, East and South China, Siam, Burma. and Bengal, eastwards as far as the 

 Andaman Islands and Sumatra (or as far as the Comoro Islands ?), southwards as 

 far as New Guinea (or as far as Queensland ?) . As for our region, it is not quite certain 

 how far this genus has invaded it by means of endemic species. Pheretima is still preva- 

 lent in the Andaman Islands and in Burma. One probably endemic species is found 

 in Bengal {Ph. anomala, MICHI^N., from Calcutta). But some other Indian species, 

 for instance Ph. alexandri (BEDD.) from Calcutta, are very doubtful. They may be 

 endemic or not : in the former case they are to be regarded only as outposts of a 

 very recent geological date. The proper dominion of Pheretima terminates in the 

 northern part of Burma. 



The geographical relations of all these genera of M egascolecince may, without 

 constraint, be arranged in four different categories : — 



