British Enchytneids. By Rev. H. Friend. 



265 



often cause a bulging of the segment. Slight variations occurred 

 in the shape of the brain and of the spermathecal ampulla ; other- 

 wise remarkably constant. 



Found March 26, 1912, at Eolleston, and May 13, 1912, at 

 Mansfield, Notts. Eecorded in Rep. and Trans. Nott. Nat. Soc, 

 lUlO-ll, p. 4:0. 



2. Fridericia reversa Friend. 



Length of adult when living 15 mm. Segments 50-65 in 

 number, of a dull grey colour. Set?e in front 4-6, frequently five 



/fit. 



Fig. 28. — Spermatheca of F. reversa Friend. 



dorsally and six ventrally. The innermost pair very small; the 

 larger hooked within. In posterior segments the setce are larger, 

 and decline in number from 4 to 3 

 and 2. Brain longer than broad, 

 convex behind, with a kind of under- 

 lap or plate, thin and delicate ; nerve- 

 chord enlarged in front. Sperma- 

 thecse with moderately long duct, 

 pear-shaped ampulla, and a pair of 

 reversed diverticula (fig. 28). No 

 glands at the opening. Salivaries 

 simple or with very short forks, 

 curving in front of the sperm athecte. 

 Dorsal vessel arises in or near the 

 21st segment (between 20 and 22). 

 Girdle with papillose glands, rather 

 large and in fairly regular rows. 

 Covering segment 12 and to setse 



of 13. Chloragogen cells very light brown, with clear spaces. 

 Coelomic corpuscles often pointed. Ampulla of sperm-duct large, 

 about 3, 4, or 5 times longer than broad ; neck or collar absent, or 



Fi . 29.— Nephridium of 

 F. reversa Friend. 



