670 OLIGOCHAETA 



Definition. Length, 3 feet, 6 inches. CUtelhm, XIII-XXVI [about). Calciferous glands 

 in X. Testes two jiairs. SpermatAecae in segments XIII-XFI, one to four pairs in 

 each. Hah. — Cape Colony. 



This is one of the few species of exotic Terricolae concerning which there is 

 already a considerable literature. The first describer of the worm was Kapp, whose 

 description, written as it was in 1848, is naturally very imperfect; it is, indeed, 

 practically confined to certain external characters, though Vaillant with quite 

 unnecessary approbation speaks of Rapp's paper as being ' trfes complete pour 

 r^poque.' It would be impossible from Rapp's paper to glean anything with respect 

 to the systematic position of the worm. The first paper dealing with the structure 

 of this worm was published in 1886 by myself (7); not long after appeared a paper 

 by Benham (2) supplementing my own in several points ; both these papers are 

 illustrated by numerous figures; my own paper contains a coloured plate of the 

 worm sketched from life. Shortly after this I examined another specimen of the 

 worm and corrected (41) a few inaccuracies in the first paper, identifying as the egg- 

 sac a structure which both Benham and I myself had described as the ovary. 

 Subsequently Benham (8) rectified an error in the enumeration of the segments, 

 definitely fixing the position of the ovary in the thirteenth segment, a position 

 which is so very constant among earthworms. 



M. rappi is the name which should be used for this species, in my opinion, in 

 spite of Vailiant's criticism ; Vaillant considered that the correct name would be 

 'Microchaeta microchaeta^ in view of the fact that Rapp's name for the species was 

 , Lumbricus microchaetus ^ ; Rapp, however, at the conclusion of his paper suggested 

 that the worm should form a genus apart from Lumbricus with the name Micro- 

 chaeta; and Peekiee (5, p. 339 footnote) made an identical suggestion; it is not in 

 accord with modern practice to use the same name for the genus and the species ; 

 and as the name M. rappi is more familiar to zoologists than the one suggested by 

 Vaillant, I shall retain it here. 



M. rappi is one of the largest, if not the largest, of earthworms ; the living worm 

 examined by myself measured about five feet ; this specimen when contracted by 

 spirit was reduced to thirty-eight inches ; the length given in the above diagnosis of 

 the species is taken from Benham's paper, which appears to represent about the 

 mean. It is common after rain in various parts of the Cape Colony, and has been 

 noted by several obsei'vers to appear only when the ground is thoroughly soaked by 

 the wet; the great bulk of the creature is probably the reason why it can only 

 move about comfortably under such circumstances. 



' But lie put it in genus Antaeus. 



