182 



Transactions. 



Fig. 



a depression of the body-wall, formed during the growth of the worm. It 



is very muscular, and is provided with muscles which connect it with the 



body-wall. It receives the two sperm- 

 ducts on its posterior face, close on each 

 side to the nerve-cord. 



Segment x is filled with developing 

 spermatozoa ; and there are two median 

 sperm-sacs — an anterior sac, which passes 

 into segment ix, communicating with seg- 

 ment x around the dorsal vessel ; and a 

 posterior sperm-sac entering segment xii, 

 and, in another individual, into segment 

 xiv. and lying below the ovisac, from 

 which, however, it is quite distinct ; it 

 does not project into it, as it does in 

 R. pilosus, for instance. 



The ovary has the normal position 

 attached above the sperm-duct, and 

 there is a large ovisac occupying segment 

 xii. in which are 2 large ova, filled with 

 yolk-spherules. In the individual cut 

 transversely, the sac extends into at 

 least the 13th segment. 



The spermatheca is paired in seg- 

 ment x ; each is a large ovoidal sac, 

 from which the duct is not distinctly 

 marked off from the ampulla externally. 

 The ampulla lies obliquely across the 

 segment, and reaches from near the 

 lateral to the median line. The duct is 

 indicated in section by the glandular 

 and muscular thickening of the wall ; 

 its diameter decreases gradually till it 

 is very slender, where it enters the 

 body-wall. The right and left sperma- 

 thecae open into a shallow, wide, 



median depression corresponding to the median spermiducal chamber. 

 In the individual sectionized sagittally, I find that the duct of 



spermatheca crosses over the median line below the nerve-cord to 



externally on the opposite side of the body. 



Other Viscera. — There is a complex system of capillary blood-vessels 



on the inner surface of the body-wall, as has been described for other 



species. The dorsal vessel lies laterally on the right side in the genital 



segments. I noted the peculiar unicellular valves in the main vessels, as 



described originally by Goodrich. 



The pharynx is surrounded by glands which fill segments iii, iv, and v, 



and the necks of these can be traced through the dorsal ciliated pad on the 



roof of the pharynx to open into its cavity. 



I have found it impossible to make out details of the nephridial 



structure, but it recalls a Tubificid rather than an Enchytraeid organ. 



The canal coils loosely, and is surrounded by enlarged coelomic epithelial cells. 

 In the body-cavity I noted a good number of round granular vacuolate 



cells, the coelomic corpuscles, which in some segments, as in those immedi- 



]0. — R. kermadecensis. Plan 

 of the male ducts, supposed 

 to be seen from above with 

 the roof of the .spermiducal 

 chamber removed. The pro- 

 portions are not accurate. The 

 organs on the right side are 

 shown in section, a, prostate ; 

 b, transverse duct; c, atrium; 

 d, cut wall of spermiducal 

 chamber; e, its external open- 

 ing. 



each 

 open 



