52 



latory bristles only upon segment XIX. Beddabd's specimens from 

 Queensland ' ) show a great resemblance of characters with those of 

 the Malay Archipelago, Beddard however could not observe the 

 bifurcation of the distal extremity of the setae; Rosa believes, 

 that in those worms the bristles had lost their tips by being 

 worn off. In support of Rosa's opinion I can state, that the bifur- 

 cation of the setae in several specimens is very difficult to observe, 

 and by no means so obvious, as figured by Pebrier; on closer exa- 

 mination of the setae for this purpose , I found , that below the tip , at 

 the concave side, some crescent ridges are present, just like in Rhino- 

 drilus (PI. IV, fig. 36). Beddard also found them in Schmabda's P. are- 

 nicola, but thought them to be absent in P. corethrurus, and suggests 

 that the first species could be distinguished by this character from the 

 latter one. Although this difference between the two species does not 

 hold, nevertheless P. arenicola may be a distinct species, as it seems 

 to have two pairs of reniform spermathecae. 



The setae in P. corethrurus are situated upon a circular zone, 

 in which, in the segments in front of the girdle, the ordinary glan- 

 dular cells of the epidermis are nearly totally absent (PI. Ill, fig. 33). 

 In this region however other peculiar structures are to be found , a't first 

 observed by Perrier in this species , and afterwards also met with by 

 Beddard in the Pontoscolex-specimens from Queensland. Those bodies 

 (PI. IV, fig. 37), which are large in the anterior segments , consist of an 

 obvious, highly refractive wall and a central body, deeply stained 

 by alum carmine. In transverse sections of the body-wall they show 

 a dome-like shape, and probably they are connected with the surface 

 by a tubular canal ; in the middle of their base the wall appears to be 

 thickened and bears the spherical central body. In the centre of this 

 structure a large , clear nucleus with a nucleolus is to be seen ; the body 

 is surrounded by another thin , unstained layer , connected with the wall 

 by some large processes. The organ lies totally embedded in the epidermis. 



Vejdowsky 2 ) at first compared those bodies with the large, pear- 

 shaped cells of Anachaeta, which substitute the bristles in this 

 worm; Beddard of course shared this opinion, because it furnishes 

 a support for his theory, according which the primitive Lumbricidae 

 were furnished with a circle of numerous setae in each segment, like 



1) Proc. of Royal Soc. of Edinburgh, Vol. XIV, 1887, p. 160. 



2) Monographie der Enchytraeiden, p. 21. 



