216 WILLIAM BLAXLAND BENHAM. 
a. The presence of nephridia in the same somites with the 
genital ducts (except in some species of Pericheta and 
Pleurocheta (Megascolex), where nephridia are unknown 
in any somite, and in Pontodrilus, in which the nephridia 
are said not to commence! till the hinder region of the sperm 
duct, so that there are none in the somite carrying the oviduct). 
b. The abundant vascular network on the nepridia and body 
wall. 
c. The almost universal presence of a gizzard (Ponto- 
drilus is again an exception). 
d. The much smaller size of the ova and the compactness of 
the ovary. 
But even these charcters may have to be altered as new 
forms are studied. 
These Lumbricine Perrier divides into four groups, 
taking as a basis the relation of the clitellum to the male pore. 
1. The Anteclitelliani (Preclitelliani), in which the male 
pore is far in front of the clitellum, include the genus Lum- 
bricus, which Eisen (15) has lately subdivided into the genera 
Lumbricus, Allurus, Allolobophora, and Dendrobena, 
as well as, doubtfully, Kinberg’s (19) genera Alyattes and 
Eurydame, and Savigny’s (1) Hypogeon. As these three 
latter genera are insufficiently described, it is doubtful whether 
the characteristics given by these authors justify the retention 
of their names. 
Whilst this group contains only a few forms, the members 
of the other groups are numerous and mostly of extra~-European 
origin. 
2. The Intraclitelliani, where the male pore is situated 
within the limits of the clitellum, include the genera Anteus, 
Urocheta, Rhinodrilus, Microcheta, and _ perhaps 
Kinberg’s Geogenia and Tritogenia. 
8. The Postclitelliani have the male pore behind the 
clitellum, and include Pericheta, Acanthodrilus, Eudri- 
1 Tt is not improbable that examination by means of microscopic sections 
would result in the discovery of nephridia in some cases where Perrier has 
failed to see them with the naked eye. 
