282 Proceedings of the Royal Physical Society. 



Oligocbseta as in other animals. Eudrilus also is a genus 

 which is to a certain extent a primitive form. The opening 

 of the vasa deferentia into the atria, and the presence of two 

 pairs of ovaries and oviducts^ are primitive characters, For 

 the present I regard the presence of Eudrihis in the tropical 

 parts of the New World and in New Caledonia and New 

 Zealand as a fact of importance in the geographical distribu- 

 tion of the genus, not caused recently by man's interference.^ 

 Another doubtful case is Urochceta. This genus occurs in 

 South America, the West Indies, the Malay Archipelago, and 

 Western Australia. The fact, however, that the Australian 

 form is specifically different from that of America, lends 

 very strong support to the view that this fact of distribution 

 is also to be regarded as normal. 



The following genera exist in more than one geographical 

 region :— 



Perichceta^ P., World-wide. 



Acanthodrilus, E., N., A., N'. Cryptodrilus, A,, O., N. (?) 



Urochceta^ N'., 0., A. 



Eudrilus, N'., A. 



Microscolex, P., A. 



Lumhricus, World-wide. 



Allolohophora, World-wide. 



Allurus, N'., P., E. 



while the following are limited to their region, with a wider 

 or more restricted range within it. 



Table of Genera peculiar to different Eegions. 



Neotropical. Diachmta. Australian. MegascoUdes. 



Urohenus. ' Phododrilus. 



Trigaster. Aporochceta. 



Afiteus. Deinodrilus. 



Geoscolex. Dichogaster. 



Onychochmta. Neodrilus. ^ 



Rhinodrilus. Anisochceta. 



^ Beddard, Contributions to the Anatomy of Eartlnvonns, No. 1 — P. Z. S,, 

 1887, p. 383. 



^ This opinion is confirmed by Michaelsen's recent description of a closely 

 allied form from Africa. 



^ I do not consider that Fletcher's genus, Perissogaster, is well established. 

 My Neodrilus is also doubtful {see Proc. Roy, Soc. Edin., vol. xiv., 1887, 

 p. 157). 



