NOTE XVII.
NEW SPECIES OF THE GENUS  MEGASCOLEX TEMPLETON (PERICHAETA SCHMARDA) IN THE COLLECTIONS OF THE LEYDEN MUSEUM  BY Dr. R, HORST.

Megascolex Sieboldi  n. s.

Cephalic lobe rounded behind, - reaching half the buccal segment.

Orifices of the copulatory pouches between the 6th and 7th, 7th and 8th, 8th and 9th segment ; opening of the oviduct indistinct. Number of setae on each segment 80, but the cincture without bristles. There are no papillae on the ventral side. The dorsal pores are commencing between the 12th and 18th segment. The copulatory pouches are situated to the number of three pairs in the 7th, 8th and 9th segment; each of them consists of two parts : a large pear-shaped vesicle, with a short duct, and a tube, somewhat longer than the vesicle and plicated like in P.  Houlleti Perr. Male genital organs placed in the 11th and 12th segment ; prostatic glands large, divided in lobes by deep incisions. The 5th and 6th septum bear groups of glandular tubes on their anterior side; the 8th and 9th septum are wanting. In the 26th segment the intestine is provided on each side with six conical coeca, placed on a trausverse series; the superior is the longest, extending forwards into the 21th segment and it seems to represent the single caecum of other Meqascolex-species.

Length 270 mm ; circumference of body 30 mm ; number of segments 135.

Hab. Japan (von Siebold).