DESCRIPTIONS OF GENERA AND SPECIES 409 



(17) Perichaeta hilgendorfl, Michaelsbn. 



p. Hilgendorfl, Michaelsbn, Arch. f. Nat., 1892, p. 335. 

 P. rokugo, Bbddaed, Zool. Jahrb. vi, 1893, -^-bt. f. Syst., p. 756. 

 Definition. Length, 150 m»z.; breadth, 6 mm.; number of segments, 120. CHtellum 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 musses of stalked glands which open hy the 

 ■pore. Setae more than 60 in segments behind clitelhm. 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 diverticulum 

 longer than pouch. Sperm-sacs. Spermiducal glands absent, sperm-ducts open on segment 

 XX (about). Hab. — 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 Michaelsbn 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 Michaelsbn ; 

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

 caeca, the sperm-sac by myself. 



(18) Perichaeta longa, Michaelsbn. 

 p. longa, Michaelsbn, Arch, f Nat., 189a, p. 239. 

 Definition. Length, 'yjomm.; breadth, 10 mm.; number of segments, 132. CHtellum XIV~ 

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

 jwres commence XIII/XIV. Intestine begins in XV; caeca long extending from segment 

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

 in VIII, IX, with long coikd diverticulum 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 /-shaped duct. Hab.—Kepiahang {Sumatra). 

 This species comes near to P- 'musica. It appears to differ from it mainly in its 

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

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

 ' slit-shaped ' pores of P. iniusica. 



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