DESCRIPTIONS OF GENERA AND SPECIES 545 



fact that the gonads are normal in position, i.e. attached to the front wall of their 

 segments. I found no egg-sacs, but as the clitellum was not developed, the single 

 specimen examined by sections was not fully mature. 



(24) Acanthodrilus ungulatus, PERKIER. 



A. ungulatus, PERKIER, Nouv. Arch. Mus., 1872, p. 85. 

 A. Layardi, BEDDARD, P. Z. S., 1886, p. 168. 



Definition. Length, i-ift. Prostomium completely dividing the luccal lobe. Clitellum, 

 XIII-XFII, complete except on last segment. Setae strictly paired, absent only on 

 segments XVII, XIX ventrally where they are replaced by the penial setae. Dorsal 

 pores commence between segments X/XI. Sperm-duct pore lies to outside of ventral pair 

 of setae. Dorsal vessel single ; last hearts in XIII. A gizzard present. Sperm-sacs 

 in X, XI, XII. Spermathecae with a very indistinctly marked diverticulum. Copulatory 

 glands and setae near to them. Penial setae ornamented with jagged cross ridges. 

 Hob. New Caledonia. 



I have no doubt that HOKST (2) is correct in identifying my A. layardi with 

 PERRIER'S A. ungulatus. The most marked peculiarity of the species is the presence 

 of copulatory setae and glands in the neighbourhood of the spermathecae. In my 

 description of the species I referred to the presence of a pair of pores upon the buccal 

 segment on either side of the prostomium ; this requires identification by means of 

 sections ; and therefore, until better preserved material is examined it is necessary 

 to lay stress upon this supposed character of the species, which is at any rate unique 

 among earthworms. The accessory copulatory structures found in the vicinity of the 

 spermathecae are by no means always developed even in sexually mature individuals. 

 I found them in various stages of development ; and HORST did not find them at all 

 in the specimens which he examined. The position of the ovary of this species 

 (perfectly normal) which I failed to find was discovered by HORST. 



(25) Acanthodrilus decipiens (NEW SPECIES). 



Definition. Length, 35 mm. ; diameter, 2-3 mm. ; number of segments, no. Clitellum, 

 XIII-XFII. Median genital papillae upon XFII, XIX, XX. Prostomium complete. 

 Setae paired, but not strictly. Dorsal pores present. Gizzard large. Neph/idia paired. 

 Spermathecae with one diverticulum of good size. Spermiducal glands extend through 

 three segments. Penial setae unornamented. Hob. Estancilla, Faldivia. 



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