424 OLIGOCHAETA 







(53) Perichaeta posthuma, VAILLANT. 



P. posthuma, VAILLANT, Ann. Sci. Nat., 1868, p. 228. 



P. afflnis, PERKIER, Nouv. Arch. Mus., 1872, p. 106. 



Megascolex afilnis, BEDDARD, Ann. Mag. Nat. Hist. Oct., 1883, p. 214. 



Definition. Length, 60 mm.; number of segments, 116. Clitellum, XIV-XFI, with complete 

 or incomplete rows of setae. Male pores preceded and followed (on segments XVII, XIX) 

 by papillae occupying a corresponding position. Male pores separated by 26 setae. 

 Setae, 140 on VIII ; 108 on X ; further back, 90. Septa, V/IX thickened. SpermatJiecae 

 in VI-IX with a diverticulum as long as pouch, tubular. Hab. Celebes ; Philippines ; 

 India; Bahamas. 



I fully agree with HORST that PERRIER'S P. affinis is the same as VAILLANT'S 

 P. posthuma; but HORST, in my opinion, is slaying the slain in showing, as he does 

 in his most recent contribution to the anatomy of earthworms, that P. posthuma, in 

 this event, cannot be confounded with P. indica. It is, as he remarks, a stouter 

 species, and the papillae in the neighbourhood of the male pores are highly distinctive. 

 The species is one of the commonest of the genus, and one obtains it in all collections 

 from the East. I have described a curious variation which this species sometimes 

 shows, in the presence of three separate spermathecae 1 in one segment and on 

 one side of the body. I have also noted a displacement of the papillae, so that 

 on one side there was an unpaired papilla in front, and on the other side an unpaired 

 papilla behind. In another specimen there were the two normal pairs of papillae 

 and an additional one upon the twentieth segment on the right side. I only found 

 setae upon the clitellum on the ventral surface of the organ, but HORST confirms 

 the earlier statement of PERRIER that there are complete circles of setae on the 

 clitellar segments. 



(54) Perichaeta houlleti, PERKIER. 



P. houlleti, PERRIER, Nouv. Arch. Mus., 1872, p. 99. 



P. campanulata, ROSA, Ann. Mus. Civ. Genova, vol. x (2a), 1890, p. 115. 

 Definition. Length, 200 mm. Clitellum,, XIV-XVI, with complete rows of modified setae (sixty 

 in each) thereon. Male pores separated by twelve setae. Setae, 17, 30; IX, 49; XIII, 54; 

 those nearest to ventral line rather longer than the others. Dorsal pores commence 

 XI/XII. Intestine commences in XV. The first septum divides segments V/VI ; this 

 and the succeeding two are thickened ; so are septa X/XIII. Spermathecae in VII-IX, 



1 I have mot with n similar variation in an undetermined species from British Guiana. 



