Tlu Classification and Distribution of EarthwoTms. 257 



I include the Eudrilini in this table, deriving them from a 

 very primitive stock, of which, however, I consider that they 

 are greatly modified members. I do this chiefly on account 

 of the reproductive organs, which show resemblances to those 

 of Leeches and Platy helminths. 



I regard the Pericheetidse as the most archaic family, not 

 wholly on account of the nephridial system, for in Mega- 

 scolides at any rate, if not in other Cryptodrilidie, the ne- 

 phridial system is nearly equally archaic. But it will be 

 noticed, from a consideration of the facts of the case, that the 

 connection between the different forms is rather easier if we 

 derive all from Pericliceta. Moreover, the complete circle of 

 setse of Ferichmta, as well as their wide distribution, is a 

 point to be urged in favour of their archaic nature. These 

 matters are more fully discussed in a paper communicated to 

 the Zoological Society of London in January of this year. 



We now come to the more difficult task of classifying the 

 remaining earthworms. It is more difiicult, because fewer 

 forms are known, and many of these are very imperfectly 

 known, e.g., Anteus and Geoscolex. 



We may clear the ground by at once admitting the 

 naturalness of the family Lumbricidse, which, as Eosa says, 

 is generally accepted. I should have regarded them, not as 

 a family equivalent to, for example, the Cryptodrilidse, but 

 as a group corresponding to that of the Acanthodrilini. 



Group III. LUMBRICINI. 



Definition. — Em'thioorms with a paired series of nephridia 

 never furnished with atria or penial setce. The setce on 

 clitellum differing from the others by their greater length. 

 Clitellum C07ninencing not earlier than the 22d segment, 

 and occupying 7-10 segments. Male p)ores upon segment 

 12, 13, 0?* 15. Gizzard at commencennent of intestine; 

 setm 8 in each segment, f-shaped and not ornamented. 



Family Lumbricidse. 



(With the characters of the group.) 



Genera — Lumbricus, L.; Alloloboj)ho7^a, Eis. ; Allurus, Eis. ; 

 Tetrago7iurus, Eis. 



