466 THE ZOOLOGIST. 



than E. minimus, and has an average of thirty segments. The 

 setae range from three to five behind, and from four to eight in 

 front. There are usually more setas in the ventral than in the 

 lateral bundles. The duct of the brownish nephridia is given off 

 by the hinder part of the postseptal. The oesophagus enters the 

 intestine abruptly at segment seven. The brain is about as 

 broad as long, straight or slightly convex behind, and concave in 

 front. There are three pairs of septal glands, and the sperma- 

 thecse are destitute of glands and diverticula. Habitat : among 

 debris by a wall in the Serpentine Walks, Buxton. 



I come now to the latest addition to our list ; and as the 

 species seems to be new to science, it is necessary to give a 

 detailed and explicit description. The worm is very small, and 

 this accounts for its specific name. 



Henlea perpusilla, sp. nov. 



External characters. — Length of adult 2-3 mm., with about 

 thirty segments. To the naked eye whitish, and in the micro- 

 scope transparent. Setae as few as two and as many as eight. 

 As a rule four to six occur, those behind being long and equal, 

 those in front being a little shorter and unequal. The girdle 

 covers the twelfth segment and reaches to the setse of the 

 thirteenth. Sometimes it falls short of the setse, at other times 

 it just exceeds them. The head is slightly glandular, but this is 

 a very variable character in all Bnchytrseids. The irregular 

 cells of the girdle are not arranged in distinct rows as is often 

 the case, nor have they the sharp definition which one finds in 

 some other species. 



Internal characters. — As the brain varies in all these creatures 

 with tension, it is best to observe the organ at rest. In the 

 present case then it is nearly or quite twice as long as broad, 

 convex or straight behind, and concave in front, as in the last. 

 The oesophagus suddenly merges into the intestine in the eighth 

 segment, and the chloragogen cells commence in the seventh; they 

 are often arranged in longitudinal rows. There are three pairs 

 of septal glands in segments four-five to six-seven, not differing 

 in any material way from the typical forms. Coelomic corpuscles^ 

 which often appear cigar-shaped or elliptical when floating, are 



