496 PROCEEDINGS OF THE NATIONAL MUSEUM vol.85 



not included in the account above but wliich probably belongs to 

 this species, has several spiral abnormalities on the anterior seg- 

 ments. On this worm there are paired presetal tubercles on vi-vii 

 or v-vi, depending on which side one counts the intersegmental 

 furrows. (On this same specimen the male-pore area on which the 

 tubercles are seated is clearly marked off by a slight but evident cir- 

 cumferential furrow.) 



Internal anatomy. — None of the septa are thickly muscular, though 

 5/6-7/8 and some or all of 10/11-12/13 are strengthened and with 

 muscular fibres ; 8/9-9/10 lacking. 



The intestine begins in xv. The intestinal caeca are compound, 

 glove-shaped, M-ith 3-5 fingerlike, anteriorly directed, secondary 

 diverticula. The dorsalmost diverticulum is the longest, and at- 

 tached to its ventral margin are 3-6 anteriorly or ventrally directed 

 tertiary diverticula. 



There is a pair of hearts belonging to ix (1 specimen), a single 

 heart on the right side (2 specimens) or on the left side (2 speci- 

 mens). The last pair of hearts is in xiii (5 specimens). All hearts 

 of ix-xiii pass into the ventral blood vessel. The hearts of x are 

 held by connective tissue against 10/11. 



The testis sacs of x and xi are unpaired and ventral. The semi- 

 nal vesicles are fairly large, filling segments xi and xii, those of a 

 segment in contact transversely over the dorsal blood vessel. The 

 prostates extend through xvii-xxi or xxii. The prostatic duct is 2-3 

 mm long, softish, a middle portion thicker than the rest, bent into 

 an S- or W-shape or almost straight. There is a pair of rudimentary 

 pseudovesicles on the posterior face of 12/13 and a still smaller pair 

 on the posterior face of 13/14, each pseudovesicle club-shaped. 



The spermathecal duct is short, narrowed gradually in the parietes, 

 and not sharply demarcated from the longer ampulla. The divertic- 

 ulum, which passes into the median face of the duct close to the 

 parietes, is longer than the combined lengths of duct and ampulla 

 and comprises a slender, smooth and glistening, firm stalk, which is 

 longer than the spermathecal duct, and a thinner-walled ental por- 

 tion, which is looped in a regularly zigzag fashion with the loops 

 short and all in the same plane. The diverticulum may be almost 

 straight with a slight suggestion of a spheroidal seminal chamber 

 at the ental end. 



Connected with each tubercle or genital marking is a stalked gland, 

 the gland spheroidal to ovoidal, usually quite small, the stalk much 

 longer, smooth, glistening and tough, erect in the coelomic cavity. 

 The stalks of the glands passing to the tubercles just in front of the 

 spermathecal pores may be much shortened and very slender or about 

 the same size and length as those of the other tubercles. 



