252 OLIGOCHAETA 



Definition. Length about 50-70 mm. Brain almost square with squarish cleft behind ; 

 anterolateral lobes, each divided into two, one directed forwards the other backwards. 

 Pharynx reaches into fifth segment. Chitinous penis eight to ten times as long as 

 broad. Hal. Europe; California; San Francisco; and Sierra Nevada. 7,000. 



I associate EISEN'S two species, Camptodrilus spiralis and C. californicus, with 

 RATZEL'S Limnodrilus claparedianus in deference to the opinion of VEJDOVSKY ; but 

 the definitions given by EISEN appear to show differences between L. spiralis and 

 L. californicus. 



As regards the European forms L. claparedianus differs from the other two by 

 the much greater length of the chitinous penis sheath ; the worm itself is also much 

 longer. These facts were pointed out by its original describer, RATZEL, though the 

 same facts about the penis sheath can be gathered from an inspection of BUDGE'S 

 plate. DIEFFENBACH (p. 98) puts down the proportions between the length and 

 breadth of the penis as sometimes 30:1, and states that in the length of this sheath 

 there are intermediate stages between L. hoffmeisteri and L. claparedianus. DIEFFEN- 

 BACH is, however, not accurate in saying that these two species in other respects 

 show an identical structure, for they differ, among other points, in the form of the 

 brain as may be seen by the figures illustrative of this organ given by VEJDOVSKY 

 (24, Tab. viii, fig. 14), and STOLC (3, Tab. i, fig. 7). The pharynx too extends farther 

 back in L. claparedianus than in L. ho/meisteri. 



(a) Limnodrilus hoffmeisteri, CLAPAREDE. 



L hoffineisteri, CLAPAREDE, Me"m.Soc. Phys. Gen. 186 a, p. 248. 

 Clitellio (Limnodrilus) hoffimeisteri, VAILLANT, Anneles, p. 424. 



Definition. Length about 35 mm. ; number of segments 95. Brain square, with shallow 

 excavation posteriorly. Pharynx reaches into third segment. Nephridia with vesicular 

 cells. Penis six to seven times as long as broad. Hob. Europe. 

 This species has been chiefly described and illustrated by CLAPAREDE and VEJ- 

 DOVSKY (24), who thinks that DOYERE described it under the name of Nais sanguinea. 



(3) Limnodrilus udekemianus, CLAPAREDE. 



L. udekemianus, CLAPAREDE, Me"m. Soc. Phys. Gen., 1862, p. 243. 

 Clitellio (Limnodrilus) udekemianus, VAILLANT, Annelds, p. 425. 



Definition. Length about 60 mm. Brain with median and lateral lobes posteriorly, with paired 

 anterior and anterolateral lobes. Pharynx reaches into fifth segment. Penis about three 

 times as long as broad. Hab. Europe. 



