812 MR. F. E. BEDDARD ON [NoV. 3, 



LumhricKS and three species of Mec/fiitcofex in a paper published in 

 the 'Transactions of the New-Zealand Institute''; but as that 

 author has merely referred to external cliaracters, it is impossible to 

 speak with certainty as to the identity or non-identity of the species 

 which I propose to describe in the present paper with any of his. 

 The practical impossibility of distinguishing species of Earthworms 

 from each other by external characters only is so well known to 

 those who have occupied themselves with the anatomy of the 

 group, that I need scarcely insist upon it here. When, however, 

 the relations of external characters to internal structure are known, 

 something may be said about the systematic position of an Earth- 

 worm from its external characters, though, speaking generally, it 

 would be unsafe to assign it to any particular genus without 

 dissection. As far as we know at present, the genus Aconthorlrilus 

 can be so distinguished ; the four male generative apertures on 

 or in the neighbourhood of the sixteenth and eighteenth segments, 

 each with the penial setoe protruding, aie distinctive of Acantho- 

 drilus. 



After reading carefully Button's description of his four species of 

 New-Zealand Lumbrici, I am inclined to think that three at least 

 do not fall within the genus Lumbricus as at present defined and 

 understood ; these are L. uUginosus^L. campestris, and L. ievis. In 

 all the clitellnm occupies from five to six segments situated in the 

 anterior region of the body between segments 10 and 2.5 ; the " male 

 genital apertures" are stated to be en the 9th segment {L. campestris), 

 the 9th and 10th {L. uliginosus), or upon the 10th to the loth 

 (/y. Ievis). The "vulvae" are upon the last two segments of the 

 clitellnm. It is possible that L. Ievis is the type of an altogether 

 new genus, but the other two species appear to me to belong to the 

 genus AcanthoJriius. What Captain Hutton, following Hoffmeister, 

 terms "vulvae" are, I should imagine, the male genital apeitures, 

 while his "male genital apertures" may be the orifices of the sperma- 

 thecae. If my suppositions are right as to the meaning of the terms 

 used in Hutton's descriptions, there is every probability that L. cam- 

 pestris and L. uliffinosiis are representatives of- the genus Acantho- 

 drilus, more particularly since this genus undoubtedly does occur in 

 New Zealand, as will appear from my own descriptions. On the 

 other hand, the fcurth species of Lumbricus {L. annulatus) described 

 by Captain Hutton does really seem to belong to the genus Lumbricus, 

 as far as one can judge from its very incomplete definition. To the 

 three species described in the present paper I give new names, 

 because they appear, so far as I can make out, to differ specifically 

 from those described by Captain Hutton ; they may prove, however, 

 to be identical ; a comparison of types can alone settle the question. 



The three species which I am now about to describe clearly differ 

 from each other sufficiently to warrant their separation as distinct 

 species. I have regarded them all as belonging to Perrier's genus 

 Acanthodrilus, because they possess four male generative apertures 

 each furnished with a prostate gland. The only other genus known 

 ' Vol. xi. p. 317 ; see also vol. is. p. 350. 



