240 W. B. BENHAM. 



are Beddard's ; and were it not that the spermathecse and 

 sperm-sacs in M. honteni occur one somite behind those 

 of M. deshayesii we might believe that he was dealing 

 with the same species. In fact, we have here another example 

 of the difficulty of accurately counting the somites in earth- 

 worms. Beddard has quite recently (October, 1889) altered his 

 previous numbers for M. barwelli, owing to the discovery of 

 a small setigerous somite following the peristomium, so that the 

 male pores of M. barwelli are, as in M. deshayesii, 

 between Somites x and xi. The spermathecal pores, too, 

 which were previously given as between vi and vii, now agree 

 with the pores of Perrier's '' anterior sperm-ducts," in being 

 placed between Somites vii and viii. 



The diagram accompanying this paper is taken from Horst's 

 figure of M. houteni, and the position of the various organs 

 differs somewhat from that in the other two species. As will 

 be seen, the sperm-sacs are in Somite xi (and probably also 

 the testes and funnels of the sperm-ducts which open externally 

 between Somites xi and xii). The ovipore is in Somite 

 XIV, and probably the ovary is in Somite xiii, these organs 

 being therefore in the normal position. Here the prostate 

 is a large structure, whilst in M. barwelli it is extremely 

 small. 



The spermatheca in Somite ix has a long duct opening 

 anteriorly. 



The " ovary" of Perrier's species is not the true gonad, but 

 the "ovisac," or receptaculum ovorum, and recalls the way 

 in which the ova push their way back through several somites 

 in Microdrili. The ovary is unknown. Beddard has figured 

 [' Quart. Journ. Micr. Sci./ xxix, pi. xi) the oviduct with its 

 funnel and external aperture ; but the numbering here given 

 is revised in the ' Zool. Anzeiger,' No. 318, where the external 

 aperture is placed on Somite xii, and the funnel in Somite 

 XI, so that in all probability the gonad is in Somite xi. 



Prof. Bourne has given us a few facts about seven new 

 species of the genus, chiefly as regards the position of the 

 gizzard, but says nothing about the genital organs. The most 



