i66 



Memoirs of the Indian Museum. 



[Vol. I, 



GKN. PBRIONYCHELLA. 



PerionycheIvIvA annandalei, Michi^sn. 



p. a., MICHAELSEN, in Mt. Mus. Hamburg, xxiv, p, 154, f. 7. 



I had one sexually mature specimen, broken into several pieces, but apparently- 

 complete. 



External Characters. ^Dimensions : L^engtli ca. 280 mm. if not more, 

 thickness 6 — 10 mm., number of segments 215 if not more. 



Colour: dorsally dark violet-blue, ventrally lighter, reddish grey. 



Head pro-epilobous, if not shortly epilobous. 



Setse of the anterior part of the body very minute, of the posterior part larger ; 

 dorsally further apart one from another than ventrally. Circles of setae in general com- 

 plete, only dorsally sometimes shortly interrupted, the two median setae standing 

 further apart than other neighbouring setae {zz > yz). Number of setae ca. 80-iv (or 

 more?), 85-x, 70-xix. 



First dorsal pore on the intersegmental furrow between segments 21 and 22 

 or more in front ?). 



Clitellum distinguished only by its darker colour, occupying segments 12 — 24 

 ( =13), developed all round the body, but at the most anterior and the most posterior 

 part ventrally less distinct if not interrupted ; anterior and posterior border of clitellum 

 not sharp. 



On the i8th segment a circular male area somewhat deepened, especially at the 

 periphery, occupies the whole length of the segment in the ventral median line. 

 The surface of this area is wrinkled, and, in the zone of the setae, 

 elevated to a small rampart. The pale colour of this area extends 

 somewhat over the surrounding surface. A pair of inconspicuous 

 male pores is situated on the lateral parts of this male area in the 

 zone of setae. Some setae are to be found between the male pores 

 on the rampart-like zone of the area. 



Sperma thecal pores inconspicuous, two pairs in the inter- 

 segmental furrows 7-8 and 8-9 very near the ventral median line. 



Internal Anatomy. — Septa in the region of the sperm-sacs 

 thickened. 



Alimentary tract: A moderately great gizzard in the 6th (?) 

 segment. CË^sophagus simple, without calciferous glands. Intestine 

 without typhlosole and caeca. 



Nephridial system meganephric. 



Anterior male organs : Two pairs of great sperm-duct- 



FiG. 13. 



Perionychella 



innandalei. 



funnels in the loth and nth segments, apparently free, not enclosed in sperm- 

 reservoirs, which seem to be missing. Paired grape-like sperm-sacs in segments 11, 12 

 and 13, suspended at the septa in front. The sperm-sacs of the 13th segment are 

 smaller than the foregoing and seem to be continuous with those of the 12th segment. 



