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BRITISH ANNELIDS. 



WITH ESPECIAL REFERENCE TO THE EARTHWORMS OF ESSEX 



By REV. HILDERIC FRIEND, F.L.S. 

 {Coiitinut'd from />age 6j.) 



nPHE genus of earthworms which now remains to be examined is 

 represented in England by no fewer than fifteen species, so 

 far as our present knowledge will allow us to judge. So large a 

 group is certain to present a considerable variety of forms, and by 

 a systematic study of each species it is possible to separate the genus 

 into three or four well marked sections, thus enabling the student 

 the more readily to identify the various forms. Before we proceed 

 to this sub-division, however, it will be desirable to obtain a clear 

 idea of the genus as a whole. As I have already indicated, Eisen 

 split up the old genus Lu mhricus m 1873, and made two new genera. 

 His nomenclature was of the most intelligible character. Selecting 

 the old Lumbricus terrestris^ L. as his type, with its head perfectly 

 mortised and tenoned into the first ring, he called all the worms 

 which had a differently formed lobe .^i//(?/(?^'///^/'f? or "Different-lobe- 

 bearers." There was one worm, however, which, while it had a 

 different lobe from that of the typical Lumbricus, and so was nearly 

 allied to the new genus Allolobophora, yet had its male pore on segment 

 13 instead of segment 15. To distinguish this genus from the other, 

 Eisen turned to its posterior extremity and found it to be sharply 

 angular. He therefore called it Allurus, or " Different-tail worm " ; 

 and hence we have the true Lumbricus as the type, with two genera 

 differing either in the shape of the head or of the tail. 



Thus, while the genus AllolobopJiora agrees with Allurus in the 

 shape of the lobe or prostomium, it differs from that genus in the 

 position of the male pore. Again, while some of the species belong- 

 ing to the genus Allolobophoi-a closely resemble the true Lumbrici, 

 they may always (with one exception, which is at present anomalous) be 

 distinguished by the shape of the prostomium. Having, in my last 

 paper, given a few of the principal characters of the genus Lumbriais, 

 I may here supply a similar account of the genus Allolobophora. 



GENERIC CHARACTERS OF THE ALLOLOBOPHORA. 

 Lip, or prostomium, only partially bisecting the first ring or peris- 



tomium. 

 Setae eight in each segment, either in couples or forming separate rows. 



