v] RELATIVE FREQUENCY 75 



into consideration in connection with the fauna of 

 Europe and not with that of tropical and south 

 temperate Africa. 



We have in the first place to consider an entirely 

 peculiar family, of fair extent in genera and species, 

 which is limited to this region of the world ; that is 

 to say with one apparent exception which is clearly 

 only apparent. The genus EudrUus is one of the 

 few kinds of worms that turns up in collections from 

 every tropical part of the world and even at times 

 from more temperate countries. It is one of those 

 1 peregrine ' forms, as Dr Michaelsen has termed them, 

 which possess unusual facilities for extending their 

 range. Presumably its real home is Africa. This 

 family is known as the Eudrilidae though by some it 

 is only regarded as a sub-family of the Megascolecidae. 

 In this family we have the following genera : Eudri- 

 loides with 11 species, Platydrilus with 11 species, 

 Megachaetina with two species, Reithrodrilus with 

 one, Stuhlmannia with five species, Notykus and 

 Bogertia with one species each, Metadrilus also 

 with but one species, Pareudrilus with perhaps five, 

 Libyodrilus with one and Nemertodrilus with two 

 species, Metschaina with two species, EudrUus with 

 two (or possibly more?) species, Parascolex with 

 four species, Preussiella with two, Buttneriodrilus 

 with two, Emmoscolex with 16 species, Hyperio- 

 drilus, Heliodr Hits, Alvania, RosadrUus, Kaffania, 



