408 OLIGOCHAETA 



surface; clitdhm yellow; these tints are largely preserved after alcohol. Clitellum, 

 XlV-Xn, with complete rows of setae. Male pores correspond to sixth seta; only 

 two setae on each side between the male pores. One pair of genital papillae jiist 

 behind and to the outside of the male pores ; on boundary-line of segments XFIII/XIX, 

 continuous with the raised area on which the male pores are situated. The seta- 

 formula: — 1, 23; r, 44; X, 50; XVI, 4.0. Dorsal pores commence XJ/XII. Intestine 

 begins in XF. Septa Y/YIII and IX/XI thickened. Last pair of hearts in XII. Five 

 pairs of spermathecae in Y-IX ; each has a single narrow diverticulum about half as 

 long as the pouch, and swollen at its extremity. The apertures which are not all accurately 

 in line, correspond to the sixth seta, and thus also correspond to the male pores. The 

 median oviducal pore {on XIF) is continued on to front end of the segment by a groove. 

 Sperm-sacs in XI, XII; sperm-reservoirs in X. Spermiducal glands occupy segments 

 XFI-XX; duet bent upon itself; the distal half of this tube is thick-walled and 

 spindle-shaped; the sperm-duct joins the commencement of the thin-walled portion. 

 Hab. — Penang. 

 The setae upon first two segments of clitellum are small, but large upon the last 

 segment. On segment x the setae are also markedly smaller than on other segments. 



(16) Perichaeta pulchra, Michaelsen. 



p. pulehra, Michaelsen, Arch. f. Nat., 1892, p. 233. 



Definition. Length, 150 mm.; breadth, 6 mm.; number of segments, 113. Male pores 

 separated by sixteen setae ; their position corresponds to about eleventh seta. Setae 

 more densely arrayed on ventral side; on XXI, 62. Dorsal pores commence XII/XIII. 

 Caeca with five or six indentations on lower margin. Septa IF/FII, XJXIII thickened. 

 Hearts in X—XIII. Spermathecae one pair in Fill, with single diverticulum not so 

 long as pouch. Sperm-sacs in XI, XII communicating with two pairs of sperm-reservoirs 

 in X, XL Spermiducal glands compact, with extremely short wide duct. Hab. — Lujon. 



This species is also marked by its colouration ; I have not, as I have in several 

 cases, included a description of this in the definition. The reason for this omission 

 is that the colour is only known in the preserved worm. Each segment is traversed 

 by a white ring which occupies the line of insertion of the setae ; the intersegmental 

 zones are purple ; on the ventral side the white zones increase in width so as to 

 ultimately occupy the whole of each segment. On the dorsal side the converse takes 

 place; the white lines get narrower and nan-ower until they are reduced to a series 

 of white spots, whence arise the setae. 



