■144 DESCRIPTIONS OF EARTHWORMS. 



this feature, because our specimen presents the main cha- 

 racters, by which the genus Moniligaster is characterized, 

 viz. a single pair of spermathecae , with a long, narrow 

 duct opening in the intersegmental groove VII/VIII ; a single 

 pair of sperm-sacs, with sperm-ducts terminating in a pro- 

 stata , which opens between segments X and XI, and a mo- 

 niliform gizzard. As stated in a preceding paper, I found 

 that in Monilig. Houtenii the oviducal pores neither have 

 the position indicated for the other species of this genus , but 

 are situated upon segment XIV. It appears to me probable that 

 the position of the oviducal pores, which nearly in all other 

 earthworms is constant on segment XIV , is liable to some 

 variation in the family of the Moniligastridae. Therefore 

 I thought it preferable to range this Borneo-worm in the 

 genus Moniligaster, and to await wether the discovery of a 

 new species perhaps might throw light on this questionable 

 point of their structure. 



July 1894. 



EXPLANATION OF PLATE 7. 



Fig. 1. Moniligaster coeruleus Horst. One of the setae, x 40 

 diam. ; 

 la. Distal extremity of a seta, highly magnified. 



Fig. 2. A nephridium. x 5 diam. 



Fig. 3. View of the right half of thirteen segments (VII — 

 XIX) of the dissected worm , to illustrate the arran- 

 gement of the genital organs, x 2^/2 diam. 



g. gizzards ; 0. ovary ; ov. oviduct ; pr. prostata ; 

 ro. receptaculum ovorum ; s. vesicula seminalis ; sd. 

 spermduct ; sp. spermatheca. 



Fig. 4. A portion of the ovary ; highly magnified. 



Fig. 5. Ventral view of the body-wall of eight segments 

 (VII — XIV), cut through along the dorsal line and 

 spread out : np. nephridiopore ; sp. spermathecal pore ; 

 rf. male pore; 9- oviducal pore. 



Notes from the Ley den ]VIuseu.iii, Vol. XVI. 



