54 fAMI-UKNIA ACAUKMV DK S( I |:N( KS. 



tliotii^li tliev can always be made out. Tlie clitclluiu comprises somites xiii to xviii. 

 tlinii'jli tlic |ios(ciior \ of xii is freiicnilly also somewhat tliickciicd. Of the aiiti- 

 clitellar somites vii, viii, ix are thicker than the others, and as thick as the somites 

 of the clitelliim. All the somites are deeply segmented, except the clitellar somites 

 ;imi lliKse anterior to ill. Tiie external pores are situated as follows: Spermathecal 

 pores, two pairs, between vii/viii and viii/ix, a little lateral of the seta 2. Ovidncal 

 ]>ores in xiv in front of seta 1, "generally in a slight depression, bordered by a swelling 

 of the body-wall. The male pore and pore for [)enial setic combined in one, open in 

 line with seta 2 in xviii. The male pore is characterized l>y being situated on an ele- 

 vated papilla more or less oblong. This papilla is surrounded by a circular depression 

 which encroaches on the two adjoining somites (xvii and xix), and this depression 

 is again surrounded by a lunar ridge, open ventrally, and extending from the center 

 of xvii to the center of xix, thus reaching slightly outside of the clitellum (fig. V2U). 

 The clitellar glands do not extend further ventrally than to a line running from the 

 center of the lunar ridge jmrallel to the sette. The ventral part of the clitellum is 

 depressed. 



Ventral popilke. One of the most interesting features of this genus are the inter- 

 sogmeiifal glands occurring on the ventral side and which in our present species are 

 paired. Tliey have possibly the same general function as the tul)creula j)upertatis of 

 the [vuv Lumbricids, or the ventral papillie of Perichieta, etc., which latter they 

 greatly resemble, but unlike the former they are variable in position, sometimes oc- 

 curring to the number of as many as seven pairs. In other specimens again they are 

 reduced to one solitary tubercle, situated on one side of the ventral median longitud- 

 inal line. Th(! most common form is as follows: 



< )ne pair between viii/ix. 

 ( )ne [)air between ix/x. 

 One pair between xv/xvi. 

 One pair between xvi/xvii. 

 One pair l>etween xix/xx. 



Other specimens ])ossessed in addition to tlii'se pairs: 

 One between xx/xxi. 

 (^ne between xxi/xxii. 



To show the vai'iabililv of tiiesc pnpill;e 1 ni\'e ibeir jilaccs in ,i tew iridi vid mil- 

 j)iekeil out at ramloni, and 1 oulv add thai (itli<i- variations occur, as may l»e expected, 

 from what is shown here. .\ II these specimens weic taken the same day ami al the 

 same locality: 



No. 1. One pair, viii/ix. 

 One pair, ix/x. 

 One pair, xv/xvi. 

 One pair, xvi/xvii. 

 ( )ne pair, xix/xx. 



