DESCRIPTIONS OF GENERA AND SPECIES 409 



(17) Perichaeta hilgendorfl, MICHAELSEN. 



P. Hilgendorfl, MICHAELSEN, Arch. f. Nat., 1892, p. 235. 



P. rokugo, BEDDARD, Zool. Jahrb. vi, 1893, Abt. f. Syst., p. 756. 



Definition. Length, Tfjomm.; breadth, 6 mm.; number of segments, 120. Clitellum XIV 

 XVI. Male-pores invisible externally. A mass of pores lies on the Vlllth segment in 

 the middle line in front of the setae and in one specimen a similar area lay upon the 

 IXth segment; these areas correspond to masses of stalked glands which open by the 

 pore. Setae more than 60 in segments behind clitellitm. Dorsal pores commence XII/ 

 XIII. Gizzard in VIII, IX; intestine furnished with caeca 6-8 in number on each 

 side lying in XXVI; it begins in segment XV. Septa IV/VII, X/XIII thickened. 

 Hearts in X-XIII. Spermathecae in VII, VIII sometimes in VI also, with diverticuhim 

 longer than pouch. Sperm-sacs. Spermiti 'ncal glands absent, sperm-ducts open on segment 

 XX (abonf). Hdb. Japan. 



There is no doubt that this species is identical with that described by myself as 

 P. rokugo. A comparison of my description with that given by MICHAELSEN shows 

 no points of disagreement. The chief character of the species is of course the total 

 absence of the spermiducal glands, which have now been found absent in eight 

 examples. MICHAELSEN'S statements as to the segment upon which the sperm-ducts 

 open are no more precise than my own. The spermatheca is figured by MICHAELSEN ; 

 the external characters, the spermatheca, the ' capsulogenous glands,' the intestinal 

 caeca, the sperm-sac by myself. 



(18) Perichaeta longa, MICHAELSEN. 

 P. longa, MICHAELSEN, Arch. f. Nat., 1892, p. 239. 



Definition. Length, yjomm.; breadth, lomm.; number of segments, 132. Clitellum XIV- 



XVI. Male pores separated by 16- setae. Setae 60 in number on segment XX. Dorsal 



pores commence XIII/XIF. Intestine begins hi XV ; caeca long extending from segment 



XXVI-XXIII. Septa IV/VII, XI/XIV thickened. Hearts in XI-XIII. Spermathecae 



in VIII, IX, with long coiled diverticitlum, reaching into segment in front. Sperm-sacs 



in XII ; two pairs of sperm-reservoirs in X, XI. Spermiducal glands occupying segments 



XVII-XIX, with long f -shaped duct. Hab. Kepiahang (Sumatra). 



This species comes near to P. mudca. It appears to differ from it mainly in its 



smaller size and in the absence of pigment, and also in the fewer setae. MICHAELSEN 



thinks that the circular male pores of P. longa are to be distinguished from the 



' slit-shaped ' pores of P. 'musica. 



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