HRITISH ANNELIDS. 63 



sil)le to secure not only the red worm, hut the new species as well, 

 which it most nearly resembles. 



The red worm has no swellings on the 15th segment where the 

 male pores are situated. The girdle covers segments 27 to 32, and 

 the band {tubercula pubertatis) extends over 28, 29, 30, 31. The 

 tail often spreads out into a spoon shape (spathulate), a property of 

 great value when it lies with the head exposed, as it can grasp its 

 burrow very firmly thereby. The bristles are arranged as in the earth- 

 worm, while the head is exactly similar in shape. This worm is pro- 

 bably more common and widely distributed than the last, though it has 

 generally been supposed that the common earthworm was ubiquitous. 



3. The purple worm {^L. piirpureus) is the smallest of the set. It 

 usually attains larger dimensions in Essex and the south of England 

 than it does further north, and I have sometimes found it impossible 

 to determine to which species a given specimen must be referred till 

 I had counted the segments preceding the girdle. A good deal yet 

 remains to be done before we can decide what influences affect the 

 size, colour, shape and structure of the different species of worm : and 

 it is, therefore, of the highest importance that collectors should note 

 carefully every detail likely to assist in the solution of these questions. 



The purple worm is usually two to three inches long. It resembles 

 the red worm in colour, shape, and general appearance. Some- 

 times it is of a pretty chestnut colour, which will account for one of 

 its synonyms {L. castaneiis, Hoffmeister). The tail is sometimes 

 more square or angular than that of L. rubeUus^ and it frequently 

 mimics the Square-tail in this respect, as well as by going rapidly 

 backwards. The girdle covers six segments as usual, viz.: 28 to t,-X)^ 

 and the band extends over 29, 30, 31, 32. The bristles are in four 

 pairs, and on the under side of segment 10 there is usually a tumid 

 growth. The male pore is not raised on papillse. In this, as in the 

 other species, a series of openings may be observed along the back ; 

 and it is sometimes important to observe the number of the segments 

 between which the first of these dorsal pores is found. The numbers 

 are given below. 



We may now summarise the characters of the genus in order thnt 

 it may be possible to distinguish it from AHolobophora. 



r,E\'ERIC CHARACTERS OF LUMBRICUS. 



Prostomium forming with the peristoniiuni a perfect "mortise and 

 tenon." 



