192 THE ZOOLOGIST. 



A NEW EARTHWORM. 

 By the Rev. Hilderic Friend. 



Aided by a Government grant, I have recently been enabled 

 to give special attention to the Annelids of Great Britain, and to 

 add considerably to our knowledge of their numbers and distri- 

 bution. In this paper I propose to place on record a new 

 discovery. So far as I can at present learn, the worm which I 

 am to describe is not only new to Britain but also to science. 

 As I first found it in Derbyshire, not far from the ancient capital 

 of Mercia, I propose to call it 



Dendrob^na merciensis, Fr. 



When first discovered it was mistaken for Bimastus eiseni, Levin- 

 sen, but a little fuller examination showed that it differed from that 

 species in important details, just as it resembled it in others. B. 

 eiseni has the head arrangement of Lumbricus, so has D. merciensis, 

 i. e. the prostomium makes a perfect mortise and tenon with the 

 peristomium, or constitutes what Michaelsen terms the " tanylobisch " 

 type. It is, however, not so pronounced as in Lumbricus. In 

 B. eiseni the girdle begins on segment 25, but sometimes as early as 

 24, in D. merciensis it begins on 24, but eventually includes two other 

 segments, and extends from 22 to 31. We have no other worm, 

 except Allurus, in which the girdle assumes such a forward position. 

 In D. merciensis the setae are not strictly paired, nor is the colour 

 of the purple Lumbricus type, which characterises B. eiseni. 



The new worm is a denizen of the leaf-mould, and may possibly 

 in the past have been mistaken for D. constricta or D. subrubicunda, 

 which it closely resembles. But it may at once be distinguished 

 from these by the shape of the head, the position of the girdle, the 

 absence of tubercula pubertatis, and the nature of the male pores. 

 These latter organs are found on segment 15, but whereas in D. sub- 

 rubicunda they are on prominent papillae, which often affect the 

 adjoining segments, in the new worm they are somewhat sunk, 

 though clearly visible. The worm is of the warm brown or chestnut 

 colour which is characteristic of this group of worms, with a ventral 

 surface free from pigment, and an absence of iridescence dorsally. 



D. merciensis has about one hundred segments, and is some two 

 to three inches in length. I have noticed two or three peculiarities 

 which seem to deserve mention. All our earthworms have their own 

 special modes of progression. Some are sluggish, others active, 

 some always follow their head, others prefer to go backwards. But 

 in the new worm I notice a peculiarity which has not been met with 

 before in our purely native worms, except in a species found in Kew 



