50 ALFEED GIBBS BOUENE. 



earthworms, twenty-three of which are species of Peri- 

 chsetidge, and with very few exceptions are species which I 

 have not found in India. As a long time must certainly 

 elapse before I shall be able to publish complete accounts of 

 all these forms, and the general views to which their study 

 has led me, I publish here a special account of some structural 

 features of Megascolex coeruleus, especially the details of 

 its circulatory system, which its great size has enabled me to 

 work out. Where I have dealt with matters other than those 

 relating to Megascolex I have, as a rule, embodied them in 



foot-notes. 



Historical and Systematic. 



There cannot be the slightest doubt but that the worm here 

 described belongs to the same genus as the worm described by 

 Beddard (1)^ as Pleurochseta Moseleyi. 



This author (2), after an examination of the type specimens 

 of M. coeruleus in the British Museum and in Edinburgh, 

 and subsequently to the publication of the paper above 

 referred to, came to the conclusion that his genus Pleuro- 

 chseta was identical with the genus Megascolex established in 

 1845 by Templeton (14). I am convinced that the species 

 also are identical, and that the name Pleurochseta 

 Moseleyi must be considered as cancelled. It is perfectly 

 true that, owing to the loss of the " Memnon," by which ship 

 Templeton despatched to England his original memoir, the 

 existing description is very scanty ; but on the one hand we 

 have Beddard's examination of the type specimens, and on the 

 other the worm is very large (the largest known Perichsete) and 

 of a striking colour, and from numerous inquiries which I made 

 on the spot is, it appears, well known to Europeans and natives, 

 and believed to be the only worm of that size in the island. 



The question of the identity of M. coeruleus with any of 



find in Ceylon, making the amazing total of about sixty-seven species ; and I 

 have no reason to suppose that the field is by any means exhausted. In the 

 town of Madras there are four species : Perichseta armata, two new species 

 of Acanthodrilus, and a minute species of Moniligaster. 



' These numbers refer to the bibliography at tlie end of tiiis paper. 



