814 MR. F. E. BEDDARD ON [NoV. 3, 



in the anterior pnrt of the body there are a larger number of pores, 

 forming a continuous ring round the body and between the setae. 



The dorsal blood-vessel is formed of two tubes which remain 

 distinct throughout the body. The pharynx is provided with a 

 large gland consisting of metamorphosed nephridia ; this opens into 

 the buccal cavity by a long duct. The intestine has uo caeca or 

 glands. 



The above descriptions contain the main specific characters of 

 these species. I shall now proceed to review their external and 

 structural characters in greater detail, comparing them with each 

 other, with other species of the genus, and with other genera. 



Part II. 



§ Integument. 



Under this head will be discussed the external characters of the 

 genus Acanthoclrihis, as well as the structure of the integument. 



Clitellvm. — In the specific definition it has been already stated 

 that the cliteilum occupies in all the tiiree species under consider- 

 ation eight segments, from the r2th to tlie 19th inclusive. In 

 other species the extent of this modified region of the integument 

 appears to be different. In A. tnigidaius it only occupies four 

 segments, from the 14th to the 1 7th ; A. biittikoferi, on the other 

 hand, has a cliteilum which is only one segment short of ^. multiporus 

 &c., reaching as it does from the 13th to the l!)th segment. 



M. Perrier, as is well known, has divided Earthworms into tliree 

 great groups, characterized by the different relations borne by tlie male 

 generative apertures to the cliteilum : in the Preclitellians the male 

 generative pores are placed in front of the cliteilum, in the Inlra- 

 cliiellians within it, and in the Postclitelii uis behind it. Now, in all 

 the tliree species oi Acanthodrilvs d,escv\heA in the present paper, as 

 well as in one species {A. sclilegelii) described by Dr. Horst, the male 

 generative apertures are placed withn the chtellum ; M. Perrier's 

 location of the genus Acanthodrilus witiiin the group of Post- 

 clitellians depends upon the examination of a single species referred 

 to above, viz. A. uvgulatus. As M. Perrier's classification in tliis 

 instance at least separates species so closely allied as A. vngulatiis 

 and A. schlegelii, or any of the species defined in the present paper, 

 it is evidently based upon characters which are not of final im- 

 portance. 



We are at present acquainted with so very few Earthworms, 

 comparatively speaking, that the time has hardly arrived for a 

 systematic arrangement of the whole group. It seems to me, 

 however, that if any primary division is possible at all, it sliould be 

 between the Preclitellian group on the one hand and the Intra- and 

 Postclitellian on the other. The two latter have a good many charac- 

 ters in common which are not shared by Lumbricvs ; as instances iDay 

 be mentioned the general presence of prostates, the position of the 

 gizzard, strung on to the oesophagus, instead of being placed at its 

 posterior extremity, the position of the testes and spermatbecse in 



