CH. I] DISTRIBUTION OF GENERA. 59 



of world-wide range ; but it is to be noted that the same 

 species exists everywhere, and that they are among the 

 most abundant of species in accidental or purposeful 

 importations of worms, thus arguing not only great 

 probability of their accidental introduction but showing 

 clearly that they can easily survive a long journey. This 

 is as far as I think it safe to go at present, but Michaelsen 

 goes further and would confine the genus Perichceta to 

 the Old World and the genus Benhamia to the Ethiopian 

 region. The genera of earthworms are thus distri- 

 buted : — 

 Palaearctic. Lumbricus, Allolobophora, Allurus (L) 1 , Ponto- 



drilus, Microscolex (C), Hormogaster (G). 

 Nearctic. Lv/mbricus, Allolobophora, Allurus (L), Mega- 

 scolides, Ocnerodrihts, Microscolex (C), Diplocardia, 

 Benhamia (A). 

 Oriental. Perichceta, Megascolex, Pleionogaster, Perionyx 

 (P), Benhamia (A), Glyphidrilus, Annadrilus (G), 

 Typhosus, Deodrilus (0), Moniligaster, Desmogaster 

 (M). 

 Ethiopian. All Eudrilidse, Microchceta, Kynotus, Siphono- 

 gaster, Ilyodrilus, Bilimba, Gallidrilus (G), Benhamia, 

 Acanthodrilus (A), Megascolex, Perionyx (P), Mill- 

 sonia, Ocnerodrilus, Qordiodrilus (C). 

 Neotropical. Mhinodrilus, Anteus, Geoscolex, Tykonus, 

 Urobenus, Pontoscolex, Onychochceta, Diachceta, Tricho- 

 chceta (G), Microscolex, Ocnerodrilus, Gordiodrilus (C), 

 Acanthodrilus, Kerria (A), Perichceta (P), Monili- 

 gaster (M). 



1 The capital letters in brackets indicate the family. 



