DESCRIPTIONS OF GENERA AND SPECIES 269 



at about the middle point there is a short diverticulum, which Vejdovsky terms the 

 ' paratrium,' and on to the summit of which is grafted the prostate ; the cells lining 

 the paratrium are larger than those which line the sac, of which it is a diverticulum, 

 though they get to be very small before the opening of the paratrium into the latter ; 

 the paratrium has presumably a very thin covering of peritoneal cells ; none are shown 

 by Stolc in his figure. The prostate is composed of comparatively few cells. Near 

 to the opening on to the exterior there is a short diverticulum to which muscles are 

 attached ; this can possibly be extruded. 



(i) Botlirioneuron. vejdovskyanum, Stolc. 



Bothrionearon vejdovskyanum, Stolc, Abh. k. Bohm. Ges. 1888, p. 43. 

 ? Monopylephorus rubroniveus, Levinsen, Vid. Med. 1883, p. 225. 

 ? Clitellio arenarius (in part.), Vaillant, Annel^s, p. 415. 



Definition. Body covered with papillae. Penial setae with hooked extremity, helow which 

 are two ridges with minute denticulations. Hah. — Denmark ; Bohemia. 



Levinsen regards as a possible synonym of this species d'Udekem's Tubifex hyalinus. 

 I cannot see in d'Udekem's definition of the species any grounds for this assumption. 

 I have elsewhere entered into the much more likely view that it is a synonym of 

 Clitellio arenarius. 



(2) Bothrioneuron americanum, Beddard. 

 B. americanum, Beddard, Ann. & Mag. Nat. Hist. Feb. 1894, p. 306. 

 Definition. Length about one inch. Male pores paired. No penial setae. No spermato- 

 phoi-es{?) Hal. — Buenos Ayres. 



Genus Lophochabta, Stolc. 



DEFiifiTiosr. Dorsal setae plumose and pectinate, ventral setae uncinate. One 

 pair of intestinal hearts in IX, in II-VII slender periviseerals. Penis 

 chitinous. 



The most distinguishing character of this genus is in the form of some of the dorsal 

 setae ; these are like those of Tubifex in being capUliform, but difier in that the seta 

 is beset with fine branches, giving it the appearance of the hairs of many Crustacea ; 

 this form of seta is unique among the Oligocbaeta, the only approach to it being found 

 in Bohemilla, where one side of the seta is furnished with such processes. The structure 



