218 DR. W. B. BENHAM OS 



There are two pairs of large and lobulated sperm-sacs in 

 segments xi. and xii. 



The ovisac in segment xiv. is rather large. 



There are four pairs o£ spermathecse (PI. 15. fig. 3 6), in seg- 

 ments VI. to IX. ; the sac is oval, with a very short duct, 

 indeed scarcely recognizable ; the diverticulum is characteristic, 

 having a long, narrow, nearly straight duct, terminating in a 

 globular dilatation. 



The spermiducal gland (fig. 3 a) is somewhat kidney-shaped in 

 outline, with three deep notches ; the penial duct is moderately 

 long, curved, and without a muscular bulb. 



The characters o£ this worm may be summarized as follows : — 



P. Ploweei, n. sp. 



Rich brown, with light chsetal bands; anterior end purple. 

 Measures 120 x 4 mm., with 116 segments. Male pores slit-like, 

 with crenate lips, on lighter flat porophores separated by 10 

 chsetse. No copulatory papillae. Pour pairs of spermathecse, 

 VI. to IX., opening anteriorly. The sac is ovate, with very short 

 duct ; diverticulum long, narrow duct, with terminal globular 

 swelling. Dorsal pore xii./xiii. Chsetal ring with dorsal 

 gap ; 40 chsetse in front of, and 45 behind clitellum. Spermi- 

 ducal gland oval, with three deep clefts ; duct curved, short ; no 

 bulb. 



Sai. Bukit Timah, Singapore. 



Affinities. — There are a considerable number of species with 

 four pairs of spermathecse ; some of these are manifestly different 

 from the present worm. Prom others it differs in smaller and 

 fewer points. It resembles in several points P. FerJcinsi, Bedd., 

 from the Sandwich Isles, which, however, has no chsetse on 

 the 16th segment. The spermathecse appear to be different, if 

 I understand Beddard's description; and though the spermi- 

 ducal gland bears some likeness, I have not observed the peculiar 

 arrangement of the sperm-ducts described by him *. But in 

 P. PerJcinsi the chsetse differ in size in various segments, and are 

 larger ventrally than dorsally. 



Prom P. padasensis, Bedd., the present worm differs in its 

 much smaller size ; in the possession of a very short duct to the 

 spermatheca ; in having only two, instead of four pairs of sperm- 



* I did not make sections of the worm, and had returned it before I had 

 examined P. Arturi and P. malamaniensis. 



