British Tubificid/i'. By Rev. H. Friend. 



275 



parts of the body, those in seoment o being to those behind as 



3 : 2. The penis-sheath, which I invariably found to be 13 x 1, is 



five times as long as the hinder setae, and nearly four times the 



length of those in front. Teeth of setse nearly equal. The chlora- 



gogen cells begin in the fifth segment or the sixth, and the septa 



4/5 to 7/8 are very stout. The segments are an- 



nulated. The intestine has rich orange cells from 



segment 8 backwards through several segments, 



giving the worm a brilliant appearance. Setae 



wanting ventrally near the male pore. Hearts in 



8 and 9, that in 8 most prominent. Pharynx seems 



to extend to the end of segment 4. Spermathecae 



similar to those of L. parvus Southern (fig. 41). 



Brain rounded, slightly concave behind and convex 



or concave in front. Large glandular nephridia 



in 6/7 and 7/8, then from 12/13 onward, omitting 



the intervening segments. The nephridia of the 



hinder segments with tiny anteseptal like that of 



Enchytrseids. 



My notes show that this species is widely distributed in the 

 South of England, from Derbyshire to Kew and Sussex. The 

 variations are less marked than in most other species. Special 

 points of interest are the setse, penis-sheath, thickened septa, richly 

 coloured orange cells to intestine, and the spermathecse. I find 

 some notes which do not perhaps rightly belong to the definition, 

 but are of interest in other ways. Thus, as to the setse ; there is a 

 difference in the shape with age. In some cases the inner sette 

 are regularly smaller than the outer, and supply a scheme which 



Fig. 41. 



Fig. 42. 



distinctly recalls that of certain Marioiiinas, or Buchholzia fallax. 

 The penis-sheath is somewhat bent towards the distal end, and 

 often shows a funnel wliich is more than twice as wide as the 

 proximal (fig. 42). Sometimes the brain reveals a rather deep 

 posterior incision. The eggs have been seen to extend from seg- 

 ments 11 to 15 incla.sive. In young specimens ventral as well as 

 dorsal setse are present on the segments carrying the sexual organs. 

 No spermatophores seen. 



1911. Friend, in The Naturalist, No. 659, p. 414. 



