1892.] SPECIES OF EARTHWORMS. 699 



of their affinity ; Gordiodrilus is clearly a rather degenerate form, 

 with no marked affinities to any other genera except to Ocnero- 

 drilns and Pygmceodrilus — an affinity which may be merely due to 

 the fact that tliey are all degenerate forms, and thus not a real 

 affinity. In any case it is remarkable that thi^ curious form of 

 glandular tissue should be limited to the calciferous glands of the 

 two genera Eudriloides and Gordiodrilus. 



As regards the rest of the alimentary canal, there are not many 

 ])oints which require notice; there is a gizzard in the fifth segment, 

 well developed and by no means rudimentary. 



The first septum lies just in front of tlie gizzard and thus separates 

 segments iv./v. ; the four septa which follow the gizzard are thicker 

 than the rest. The nephridia are tif course paired, and the first 

 pair appear to belong to the fourth segment. 



There is only a single pair of testes, which lie in tlie xith segment, 

 attached to the front wall of that segment ; opposite to them are 

 the funnels of the sperm-ducts, these are very large and much folded. 

 The sperm-duct has no swelling at its origin from the funnel ; it is 

 a narrow tube, much narrower than the oviduct; it opens into the 

 atrium a little way before the opening of the latter into the terminal 

 copulatory apparatus. The atria are two closely applied tubes 

 contained within one sheath, so tliat on a dissection the atrium 

 would no doubt appear to be single. Wliether the division of the 

 atrium is an indication of its being the result of the fusion of two 

 separate atria is not obvious ; at first sight it does appear to be 

 obvious, but it will be remembered that in Eudrilus each atrium 

 is similarly divided into two completely separated tubes withm a 

 common sheath. This atrium consists entirely of a layer of gland- 

 ular cells ensheathed in a very thin peritoneal layer ; the terminal 

 apparatus is a muscular diverticulum of the body-wall, with which 

 are also connected a pair of sacs each containing a single penial seta, 

 vyhose shape I am unable to describe. 



The spermatotheca is unpaired, it opens on to the exterior in 

 segment xiii. ; the aperture leads into a thick-walled sac from which 

 arises a thinner-walled sac extending backwards into the next 

 segment ; this latter is lined by cells which appear to be similar to 

 those found in the corresponding organ of other Eudrilidse, and 

 suggest that in this species as in others the spermatothecae are 

 developed from the coelom, and are therefore not homologous with 

 the spermatothecse of other Earthworms. The terminal sac of the 

 spermatotheca is lined by an epithelium which has preserved the 

 characters of the epidermis whence it is derived ; the cells are of 

 two kinds, the usual glandular and the interstitial cells. 



To the spermatotheca on each side is attached a receptaculum 

 ovorum ; these sacs, although attached to the spermatotheca, are not 

 really connected with it, tiiat is to say they do not open on to the 

 spermatotheca ; the egg-sacs are not in any way unusual in their 

 structure, their cavity is divided up into numerous compartments by 

 trabeculse. In the compartments are lodged the ova: the ova in 

 the egg-sacs are not accompanied by masses of developing ova or by 



