MEGADRILI 



385 



Zealand) has twelve chaetae in each segment. Diplocardia, from 

 North America, has the male pores on segments 18, 19, 20. 



FAM. 12. Eudrilidae. 1 This is perhaps the most remarkable 

 family of terrestrial Oligo- 

 chaeta. Its distribution is 

 no less curious than its struc- 

 ture. Up to the present it 

 is not known outside tropi- 

 cal Africa, with the excep- 

 tion of the genus Eudrilus 

 itself, which is almost world- 

 wide in range. As, how- 

 ever, but one species of 

 Eudrilus is found out of 

 Africa, and as that species is 

 so common in gatherings 

 from various tropical coun- 

 tries, it seems to be an in- 

 stance of a species with large 

 capacities for accidental 

 transference from country to 

 country. The type genus, 

 Eudrilus, has been known 

 since 1871, when it was 

 originally described by M. 

 Perrier. 2 Since that date 

 nineteen other genera have 

 been described from Africa 

 by Dr. Michaelsen, Dr. 

 Rosa, and myself. The most 

 salient external character of 



the group, not universal 

 , i . , . j 



but general, is the unpaired 

 male and female orifices. The 

 orifices are commonly very conspicuous (see Fig. 197). 



The peculiarities of internal structure mainly concern the 

 reproductive organs, the differences in which from genus to 



1 For a general account of the Eudrilidae, see my Monograph of the Order Oligo- 

 chaeta, Oxford, 1895. 



" Nouv. Arch. Mus. Paris, viii. 1872, p. 5. 

 VOL. II 2 C 



FIG. 197. Libyodrttus violaceus F. E. B. x 2. 

 sv, Spermathecal pore : cl, clitellum ; cJ, male 



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