138 Memoirs of the Indian Museum. [Voi.. I, 



membrane. At first sight these more complicated spermathecse of the two species 

 of Moniligaster and of some species of Drawida call to mind the complex spermathecse 

 of most MegascolecidcB, which are composed of a main pouch (ampulla and duct) 

 and one or more diverticula. The question now arises, which part of the Moniligaster- 

 spermatheca must be regarded as homologous with the main pouch, and which with 

 the diverticula of those Megascolecid-spermathecse ? In the Megascolecids the 

 diverticula have in general the function of storing the sperm masses received in the 

 copulatory act, whilst the ampulla of the main pouch contains principally granular 

 masses, which are probably secreted by its own walls. In a series of sections through a 

 spermatheca of Moniligaster perrieri I studied the corresponding state in this species 

 microscopically. The long-stalked, pear-shaped pouch in the eighth segment was filled 

 with fibrous masses, the fibres of which were in general very fine but partly (probably at 

 one end) thickened, and doubtless represented clusters of sperms, perhaps embedded 

 in protoplasmic substances, which were apparently coagulated by the preserving 

 process. The branched tubes forming the paired appendices of the muscular atrial 

 chamber were in general empty ; I could see only a few coarsely granular masses in 

 them, which I think were glandular secretions. The whole structure, which corresponds 

 very well with the figure given by PBRRIER {I.e., pi. iv, fig. 80), seems to be glandular. 

 The muscular atrial chamber with its two outgrowths was empty and appeared to 

 be similar to the copulatory pouch figured and described by BENHAM in Moniligaster 

 indicus {Drawida robusta sub-sp. indica). There can be no doubt that the pear-shaped, 

 long-stalked pouch in the seventh segment of Moniligaster perrieri as well as of all 

 other Moniligastridce corresponds functionally with the diverticula of the Megascolecid 

 spermatheca, being the magazine of sperm masses received in the copulatory act. The 

 atrial cavity, on the other hand, may act as a copulatory pouch, corresponding func- 

 tionally with the muscular duct of the main pouch of the Megascolecid spermatheca, 

 whilst in some species of Drawida, and more so in the species of Moniligaster, a secretory 

 function is added, being confined to special organs — the glandular branched tubes — only 

 in Moniligaster. The functional correspondence justifies my former supposition that 

 the pear-shaped, long-stalked pouch did not correspond with the main pouch of the 

 Megascolecid spermathecse, but with its diverticula, and that the muscular atrial 

 cavity with its eventual appendices represented the main pouch, which, according 

 to this supposition, is often aborted in the Moniligastridce.^ On the other hand an 

 essential fact is not in agreement with this view. In the Megascolecids the main 

 pouch is the constant part of the spermathecse, the diverticula often being absent. 

 In the Moniligastrids the pear-shaped, long-stalked pouch is the only constant part 

 of the spermathecse, in most of the species representing the whole spermatheca, 

 and it is just in the most archaic genus Desmogaster that this is the case. We 

 cannot therefore but assume that this pear-shaped, long-stalked pouch is the organ 

 homologous to the simple spermatheca of such more archaic Oligochseta as the 

 PhreoryctidcB , as well as the main pouch of the Megascolecids, even if it corresponds 



1 W. MICHAELSEN, Neue Oligochaeten und neue Fundorte alt-bekannter; in Mt. Mus. Hamburg, 

 bd. xix, p. 9. 



