CH. I] ETHIOPIAN EARTHWORMS. 67 



New Caledonia; in all of these countries there is one 

 species apiece of Acanthodrilus. This genus is unusual 

 though not unique among earthworms by reason of the 

 fact that it is largely aquatic in habit though mainly 

 terrestrial ; even the same species, as for example Acan- 

 thodrilus georgianus, may be at once aquatic and terrestrial. 

 This naturally adds to their facility for dispersal. The 

 genus Benhamia is almost entirely African, that is to say 

 " Ethiopian," in range ; it is true that one species, 

 Benhamia bolavi, has been met with in Europe ; but there 

 can be hardly any doubt that this species has been 

 accidentally imported ; there are also two or three species 

 in Mexico and the East Indies ; Dr Michaelsen thinks that 

 these owe their presence in the countries mentioned to 

 the effects of commerce and not to their own unaided 

 exertions. Finally in North America there is the singular 

 and somewhat aberrant genus Diplocardia, which consists 

 of but a single species. 



The most remarkable case of a restricted distribution 

 among the Oligochseta is the family EudrilidaB, which with 

 the single exception of the genus Eudrilus is not to be 

 met with outside of the Ethiopian region. As this genus 

 Eudrilus is one of the commonest forms in gatherings of 

 earthworms from several parts of the world, and as the 

 species found outside Africa do not differ specifically, I am 

 disposed to regard Africa as the proper home of this genus 

 also, and to look upon the exotic specimens as having been 

 accidentally carried thither. So far as our present know- 

 ledge goes, there are no forms outside of Africa which show 

 any particular resemblance to the EudrilidaB. This family 



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