ZooL.-VoL. II.] EISEN—OLIGOCHMTA. I95 



swelling. Of these swellings those surrounding the prostate 

 pores and penial setae are the largest and sometimes appear 

 as elevated papillae. There are no real elevated papillae in 

 the surrounding somites in any of the specimens; in their 

 place are small, round fields, semitransparent and undoubt- 

 edly of a nature similar to the papillae. Of these fields 

 there are two very closely joining in XVII, posterior to the 

 setae and occupying the continuation of the ventral interval 

 a-a. Two similar areas are in XXI, while in XXII there is 

 a more oblong area, median in position, covering the whole 

 ventral interval a-a posterior to the setae. Only the speci- 

 mens most fully developed possess these flat papillae. 



Set(B. — The common setae are like those of D. singularis, 

 but the ventral interval a-b is less than half that of the 

 lateral interval b-c. According to Ude, in D. singularis 

 a-b is equal to one-half of b-c. The setae are all sculptured, 

 but the sculpturing is more in the shape of notches than 

 that represented inUde's figure 11. The shape of the setae 

 is also different, the posterior part being much heavier in 

 D. caroliniana. 



The penial setae (figs. 139, 140) differ somewhat from 

 those of D. singularis. They are about three times as long 

 as the common setae. They are more pointed than those of 

 D. singularis as figured by Ude and the apex is more 

 twisted. The most important difference is found in the 

 sculpturing of the setae, which are not smooth as in D. sin- 

 gularis. The sculpture is represented in fig. 140. It does 

 not begin at the apex, but some distance below it. There 

 are from eleven to fourteen small distinct notches on either 

 side. The two setae in each bundle are practically alike. 



Internal Characters. 



SfermatheccB. — (figs. 141 A and B.) There are three pairs 

 of spermathecae as in D. singularis, situated in somites VII, 

 VIII and IX, with the pores in front of the setae. They 

 differ in shape from those of D. singularis, being much 

 longer and narrower, and with the exception of those in VII, 

 extending through two somites instead of being confined to 



