306 MR. F, E. BEDDARD ON NEW OR [May 18, 



deferentia on eacli side, which were invariably extremely conspicuous ; 

 the two vasa deferentia of each side remained perfectly distinct, and 

 could readily be traced as far as the prostatic gland, into which they 

 open. Tlie latter structure is a tubular organ of a nacreous appear- 

 ance, lying behind the generative orifice, and occupying some five 

 or six segments ; it communicates with a large rounded pouch-like 

 structure (figs. 1, 2, h), which overlies the generative pores on either 

 side, by a narrow duct. Tlie prostatic gland is constricted at about the 

 middle of its extent, and it is at this point that the vasa deferentia 

 open into it. M. Perrier has accurately figured the appearance 

 presented by the ' bursa copulatrix ' when its upper wall has been 

 removed {loc. cit. pi. ii. figs. 27, 28). I find that the duct of the 

 prostatic gland is continuous with the curved penis (woodcut fig. 2), 

 while the rounded pad (c) which lies behind the penis receives tlie 

 duct of a peculiar glandular body (a), which is eitiier horseshoe- 

 shaped as in fig. 2 or Y-shaped as in fig. 1. This glandular appendix 

 has been referred to by Perrier, who did not, however, succeed in 

 making out its relations with the bursa copulatrix ; neither has 

 M. Perrier figured or described the termination of the prostatic 

 duct in the penis. 



A. Additional Note on Microch^ta rappii, F. E. B. 



Since my paper on the structure of this Worm was communicated 

 to the Society, Mr. Benham has published a careful and detailed 

 account of its anatomy. 



The description of the female generative apparatus which Mr. 

 Benham gives' agrees in the main with my own description, which I 

 have left unaltered in the paper. A structure which I identified 

 with the oviduct — a pair of ciliated funnels on the posterior wall of 

 segment 12 — has appeared to Mr. Benham not to be really an ovi- 

 duct but to be related to a glandular structure on the anterior 

 septum of segment 12, possibly serving as tlie excretory duct of 

 its products. On the other hand, the structure described by myself 

 as an ovary, lying in the segment behind that which contains the 

 presumed oviduct (Trans. Zool. Soc. vol. xii. pt. 3, pi. xv. fig. 4, o), 

 is also identified as such by Mr. Benham. 



I am now inclined to think that both Mr. Benham and myself 

 were wrong in that identification, and that the supposed ovary 

 really corresponds to what has been termed by Bergh ^ the recepta- 

 culum ovorum. In the first place, Mr. Benham remarks that the 

 ova which completely filled this supposed ovary exhibited no grada- 

 tion in size among themselves such as is to be seen in the ova of Lum- 

 hi'icus ; in the second place, I have observed this structure in another 

 example of the worm, recently received at the Gardens from the 

 Rev. G. H. R. Fisk, where it luas entirely devoid of ova. I cut a 

 careful series of sections through the 'ovary' and oviduct, and could 



' Quart. Journ. Micr. Sci. 1886, p. 279, pi. xvi. figs. 7, S, 14. 

 ^ Zool. Anzeiger, no. 220, p. 232. 



