214 DK- W. B. BENHAM OK 



The ch^etae are set in a prominent ridge — perhaps due to the 

 excellent preservation of the worm. There is a small dorsal 

 gap, but no ventral one. The chsetae are more closely set 

 centrally than dorsally. 



There are 38 chaetse on segment ii. 

 40 „ „ T. 



,. 54 „ „ sii. 



62 „ „ XXV. 



Internal Anatomy. — There is nothing very striking in regard 

 to the septa: septal glands occur in segments iv., T., vi. ; the 

 gizzard is relatively large, bell-like in shape, and appears to 

 occupy segments viii., ix., and x. The intestine is distinctly 

 sacculated after the 14th or 15th segments, but narrows in the 

 26th and 27th. In the latter segment a pair of large cseea 

 arise, and extend forwards into segment xx. ; their lower faces 

 are slightly notched. Behind the 27th segment the intestine 

 again enlarges. Above the intestine, on each side of the dorsal 

 vessel, after the 27th segment, is a pair of racemose (" glyco- 

 genic") Phagocytar organs * in each segment, containing abundant 

 pseudonaviculae. 



There is a conspicuously large "heart" in segment xiii., and 

 there are two smaller " hearts " in the preceding segments. 



The genital organs present two interesting features, viz. : the 

 very large size of the spermatheca, and the great development 

 of the " muscular bulb " of the spermiducal gland. 



The sperm-sacs lie in segments xi. and xii., and the testes in 

 the usual segments. 



The spermiducal gland (PI. 16. fig. 6«) is in two distinct lobes, 

 as in P. Arturi, and from each a delicate duct passes away to 

 unite together to form a larger " penial duct," which, after 

 passing some little distance backwards, bends upon itself and 

 becomes much thicker and more muscular (d) : it then runs 

 forwards to open into the middle of the outer margin of a great 

 glandulo-muscular sac (b) ; this extends from segment xv. to seg- 

 ment xix. and presents three slightly marked subdivisions, namely, 

 two terminal which contain each a great gland, and a smaller 

 middle one, the " atrium." Sections through this structure 

 show the same general arrangement as in P. Arturi — i. e., the 

 penial duct penetrates its wall, and projects freely as a " penis " 

 * Schneider, Zeitschr. f. wiss. Zool. Ixi. 1896, p. 363, describes these organs 

 for P. indica. 



