348 OLIGOCHAETA 



part of nep/tridium long and stout with coiled duct, duct of nephridium arising just hehind 

 septum. Spermathecae with many diverticula, at base of duct one large gland {or many 

 snudl glands). Hai. — Norway. 



This species is very nearly akin to the last; it is, indeed, a matter of no little 

 difficulty to distinguish them by the descriptions given. Michaelsbn distinguishes 

 them by the ' absence ' of any glands at the external pore of the spermatheca in 

 F. ratzdi, these structures being present in F. dura. Eisen, however, figures 

 a few small glands in this position in F. ratzeli (PI. xii. fig. 22 c). This point 

 is still further confused by Ude's statement that F. ratzeli has two stalked glands 

 instead of the many figured by Eisen. Another point of difference urged by 

 MiCHAELSEN is that the brain of F. dura is triangular, while that of F. ratzeli 

 is oval, and longer than broad. The number of setae also is greater in F. ratzeli. 

 If the supposed difference in the brains has no existence, it will, I think, be necessary 

 to unite the two species. 



This species, like F. ratzeli, F. callosa, and E. hegemon, has a double layer of 

 longitudinal muscles. The salivary glands are stated by Michaelsen to be like 

 those of F. callosa. 



(11) Pridericia hegemon (Vejdovsky). 



Enchytraeus hegemon, Vejdovskt, SB. Bohm. Ges., 1877, p. 303. 

 E. (Neoenchytraeus) hegemon, Vaillant, Annel^s, p. 357. 

 Pridericia hegemon, Michaelsen, Abh. Nat. Ver. Hamb., 1889, p. 44. 



Definition. Length, opmm.; setae, 4 per bundle. Anteseptal part of nephridium short, with 

 straight duct. SpermMhecae very numerous with stalked diverticula, with a pair of large 

 glands at external pore. Hob. — Bohemia ; Germany. Terrestrial. 



This species is very distinct from any other; its chief characteristic is the very 

 numerous stalked diverticula. The species has been studied by Vejdovsky (3) 

 and Michaelsen (4). The brain is oval in contour, with a marked projection 

 anteriorly, and is convex posteriorly. The salivary glands are much branched — 

 more so than in any other Fridericia. The dorsal blood-vessel springs from the 

 peri-intestinal sinus in the eighteenth segment; in this segment, and in the 

 seventeenth, sixteenth, fifteenth, fourteenth, are heart-like swellings which are also 

 developed, though to a less extent, in the two segments lying in front of these 

 again. There is an organ of taste in the buccal cavity similar to that of other 

 species of Enchytraeids. 



