948 NOTES ON AUSTRALIAN EARTHWORMS, 



Clitelluui comprising at least four segments, xiv to xvn, and some- 

 times in addition the posterior portion of xin, or superiorly just the 

 anterior of xviii, margin or even both may be included in it ; 

 incomplete on the median ventral surface. One very small specimen 

 (34 mm. long) has a very good clitellum which takes in a small 

 portion of xn and includes xvn. As is the case with Didymogaster 

 and Notoscolex grandis, after the breeding season the clitellum 

 disappears ; whereas in our Lumbricus and in other Australian 

 worms it seems to be a more permanent structure. 



The setae from different regions vary slightly both in shape and 

 length. From the posterior region they are about "35 mm. long, 

 and shew the usual slight sigmoid curve with divergent tips, the 

 imbedded end being blunt. From a few segments in front of the 

 clitellum they are straighter, slightly longer (*56 to *63 mm.), 

 with the enlargement about the middle more conspicuous ; 

 arranged in eight rows forming four couples, two ventral and two 

 lateral ; the setae of the two outer couples further apart than 

 those of the inner ones as in Notoscolex, and not at equal distances 

 as in Lumbricus. Segments setigerous after the first. The curved 

 penial setae presently to be mentioned, are, without allowing for 

 the curve, twice as long (1*26 mm.) as the ordinary ones. 



The ventral portion of xviii carries three pairs of pores of which 

 the first and last on each side are in a line, and are just dorsad of 

 the second row of setae ; they are either the pores of accessory 

 glands, or the penial setae may be protruded through them. The 

 middle pair, presumably the male pores, are closer to the median 

 line, and correspond with the intervals between the setae of the 

 ventral couples ; all three pores on each side situated on the same 

 eminence, and visible in worms without clitella. In one specimen 

 there is a swollen ridge on the ventral surface of xix ; in another 

 there appear to be a couple of pits or perhaps pores on this 

 segment, with something similar on xvn. Oviducal pores two on 

 xiv, in front of the line of setae, and a little ventrad of those of the 

 innermost rows. Spermathecal apertures two pairs, between vn 

 and vin, and vm and ix, just dorsad of the line of the innermost 

 rows of setae. Dorsal pores after about xn. 



