306 EEV. H. FRIEND OH" A 



Cinqulum prominens, e sex segmentis (34-39; semper con- 

 fectum; infra duobus parallelis tuberculis, in segm. 35, 

 36, 37, 38. 



SetcB bin 88 approximatse. 



Segmenta circa ] 00-120. 



Longitudo circa 10 cm. 



JPriina foramen dorsi inter segmenta 5-6. 



Like the other true species of Lumbricus, this worm is an- 

 teriorly of a purplish-brown colour, iridescent, especially on the 

 dorsal surface, and lighter along the hinder quarter as well as 

 ventrally. The colour of the girdle or clitellum is a warm brown, 

 corresponding closely to that of the posterior extremity, but 

 somewhat darker than the ventral surface of the worm's body. 

 The prostomium or cephalic lobe forms a perfect " mortise and 

 tenon" with the first or buccal segment, which is, as usual, 

 without setae. 



The term "mortise and tenon" is a much more accurate one 

 than " dovetail," which Benham employs. The latter is the more 

 appropriate term, however, for the species of Allolohophora. 

 It may be here pointed out that every known species of Luni- 

 hricus is distinguished from all other species of British worms by 

 the presence of an iridescent purple-brown colour, inseparable 

 from the " mortise and tenon " arrangement of the anterior 

 extremity, and coupled with a girdle of six segments, tuhercula 

 puhertaiis forming a band across the inner four, setae in four 

 closely approximated couples, and the ability to secrete a slimy 

 mucus, but not a turbid liquid. Internally there are two pairs 

 of spermathecae and three pairs of sperm-sacs. As I have 

 already pointed out*, the ^o-cdl\edi Lumhricus Eiseni, Levinsen, 

 is not a true Lumhricus, although it resembles that genus of 

 worms in one or two particulars. 



In shape and size this species is exactly intermediate between 

 the common earthworm {L. terrestris, L.), as defined hereafter, 

 and the red worm {L. ruhellus, HofEm.). It may in fact be 

 readily confounded with the latter at first sight, just as the red 

 and purple worms were, till Eisen pointed out their distinctive 

 characters. The setae are always in couples, the individuals of 

 which are nearly close together, while each couple is separated 

 by a moderate interval from the next, as in each of the other 

 species. 



* " On the Tree-worms of Great Britain," supra, p. 302. 



