330 OLIGOCHAETA 



(i) Marionia sphagnetoram (VEJDOVSKY). 



Pachydrilus sphagnetorum, VEJDOVSKY, SB. Bohm. Ges., 1877, p. 304. 



P. (Archienchytraeus, EISEN) sphagnetorum, MiCHAELSEN, Ench. Mob., 1 886, p. 43. 



M. sphagnetorum, MICHAELSEN, Abh. Nat. Ver. Hamb., 1 889, p. 29. 



Definition. Length, 15 mm.; number of segments 50; setae, 3-4 per bundle. Duct of 

 nephridium long, and arising jitt behind septum. Gonads moved a, few segments in front 

 of usual position. Hah. Germany. 



The examples of this species studied by VEJDOVSKY were sexually immature ; 

 but this deficiency in our knowledge of the species was filled up later by MICHAELSEN. 

 MICHAELSEN'S observations were conducted upon what he considered to be a variety 

 of the species to which the name ' glandulo$a' was applied, but he was able, in 

 the same paper in which his results were described, to state that the same 

 characters were to be found in the typical form l sphagnetorum.' The variety 

 ' glandulosa' is a stronger worm than the type-form ; it measures 20 mm. as against 

 1 5 ; the number of setae in a bundle are two or three instead of three or four. The 

 principal difference, however, between the two forms is in the septal glands; in the 

 type there are five or six pairs of these glands, a pair to each segment ; in the 

 varietal form about nine pairs, owing to the fact that the duct connecting the 

 several glands of one side of the body have given rise to additional glands. The chief 

 character of the present species is in the abnormal position of the sexual organs, 

 which have, as in Buchholzia appendiculata, been moved a few segments in advance 

 of the normal position. They are not, however, constantly found in one particular 

 segment ; in some individuals they are three, in others four segments, in front of 

 those which contain them in other Enchytraeids. As in the Buchholzia the spermathecae 

 have preserved their normal position. The latter are composed of a very long and 

 narrow tube, which swells out at the blind extremity into an oval pouch which 

 does not communicate with the gut ; a little way in front of the external pore 

 (which has a mass of glands on one side) the tube has a spherical dilatation. These 

 spermathecae are strikingly like the spermatheca of Anachueta bohemica minus 

 the terminal pouch through which the tube opens on to the exterior 1 . The funnels 

 of the sperm-ducts are about three times as long as broad. The duct of the 



1 In a longitudinal section of the spermatheca (optical) figured by MICHAELSEN (3, Taf. xxiii, fig. 2 c) 

 the lumen of the spherical swelling is reduced by a projection into it of a plug containing distal part of duct. 

 This arrangement would seem to facilitate entrance of sperm into spermathecae, but to hinder its exit, at 

 until there is sufficient to fill the crescentic lumen of the dilatation. 



