THE EARTHWOEMS OF THE MALDIVE AND LACCADIVE 



ISLANDS. 



By Frank E. Beddard, F.R.S., Vice-Secretary of the Zoological Society of London. 



I BELIEVE that no collection of earthworms from these islands has ever been reported upon. 

 I am therefore particularly obliged to Mr J. Stanley Gardiner and his colleagues for the con- 

 siderable collection of these Annelids which they have made with so much care and have been 

 so good as to place in my hands for study and description. 



I have no general conclusions of importance to urge as a result of my examination of this 

 collection, save to emphasise the belief, now becoming firmly founded, that these Annelids on 

 account of the practical impossibility of their unassisted migration over tracts of sea will serve 

 as the very best test of whether a given isolated island is truly oceanic or not. This is 

 however subject, as Dr Michaelsen has pointed' out, to one exception and that is the genus 

 Pontodrilus. This genus, of which several species are now known, as a rule but not always 

 lives upon the sea-shore in decaying sea-weed and such like dehris; the nature of its habitat 

 therefore precludes any impossibility of chance migration from the shores of one tract of land 

 to the shores of another. 



The present collection contains one undoubtedly new species of this nearly ubiquitous 

 genus. And that is the only new form which I have found among the three species of 

 earthworms upon which I report here. The rest are precisely what might be expected from 

 the proximity of the islands to Ceylon and India; the two species are both of them common 

 Oriental species. It is very probably in part the abundance of Megascolex mawitii which has 

 led to its so wide range. But the relations between the ease with which various species 

 can be transported to regions of quite a different climate and flourish there and other con- 

 ditions have not yet been guessed at. The material in the way of fact is at present hardly 

 sufficiently large. 



1. Pontodrilus laccadivensis n. sp- 



I have examined a large number of examples of this- species which I at first took to 

 be Dr Michaelsen's P. viutshusimensis, var. chathamianus^ on account of the nearly similar 

 disposition of the anterior genital papillae. There is, however, not an exact correspondence 

 in the position and number of them, while other features in the organisation of this Ponto- 

 drilus from the Laccadives forbid its identification with Michaelsen's variety. There is no 

 other species to which it presents so close a likeness in external characters. 



It is a long, slender species like other Pontodrilus, of 90 to 110 mm. in length. The 

 prostomium impinges slightly upon the buccal ring. The clitellum occupies segments XIII — 

 XVII, and there is always a ventral band left devoid of modification. I have studied 13 fully 

 mature examples of this species, all of which show some of the anticlitellian papillae which 

 distinguish this species from all other Pontodrilus except Michaelsen's variety. These papillae 



1 Zool. Jahrh. Syst. Ahth. xii. p. 220. 



