British Tubificidx, By JRev. H. Friend. 281 



Microscope, however, the very large coelomic corpuscles arrested 

 attention, and I find the following notes taken on that occasion, and 

 afterwards when I found that my discovery had been anticipated : — 



" Meganyniplia paehydriloides g. et sp. n. Length 8-10 mm. 

 Adult. Pale coloured, resembling a small Pachydrilus or Mario- 

 nina. Segments 45. Blood red. Setae 3, 4, 5 throughout, slender, 

 forked, upper tooth longest in anterior bundles, teeth about equal 

 posteriorly. Chloragogen cells begin in 5 or H. Coelomic cor- 

 puscles large, globular, dark, at first sight suggesting encysted 

 Gregarines, as found in Enchytraeids at Sutton Broad. A pair of 

 penial setae looking like pruning knives. Forked dorsal setae 

 present on this segment. Brain very glandular and motile, chang- 

 ing with every movement, deeply lobed behind. Spermathecae 

 roundish or pear-shaped with large aperture, not rounded but slit- 

 like. Vascular system differing from typical Tubificid. First 

 commissure from dorsal vessel in segment 2. Nephridia extending 

 through more than one segment. Dilating hearts wanting. 



I have made a few measurements which are of interest. Tlie 

 ordinary setae are nearly half the length of the penial. The penial 

 setae are the length of the spermathecae when they assume the pear- 

 shape, and are empty. The diameter of the large ccelomic cor- 

 puscles averages about half the length of the ordinary setae. The 

 setae behind are prominent, and extend a good way beyond the body- 

 wall. In front they are about one-seventh the diameter of tiie 

 body. Five or six corpuscles will li^in a row in the cadom behind, 

 while 12-14 would be needed to reach across the diameter in front. 

 As confirming Ditlevsen's surmise about the spermathecae, I may 

 say that in November I found them full of a glairy substance, but 

 without spermatophores. In segment 16 I observed some organs 

 which were new to me, and need further study. 



Bretscher, whose notes have a misprint, gives the segments as 

 30 (at least, so I understand his 3), and I have drawn attention 

 (Nature, November 16, 1911, p. 78) to the difference between the 

 Swiss and English types in this respect. I do not know how to ex- 

 plain Bretscher's remark that a large penial seta is found ventrally 

 on either side in segment 10. I find them in segment 11. Piguet 

 draws attention to this in his description of another species (Eev. 

 Suisse, 1906). It must, I think, be a slip of the pen. 



British Records. — At present known only from two little 

 streamlets on the borders of Derbyshire and Leicestershire ; Nether- 

 hall, summer of 1911 ; and Netherseal, with the next, No\ ember 

 29, 1911. 



2. Rhyacodrilus dichxtus sp. n. 



A small, delicate worm, 6-8 mm. in length; segments 35 in 

 number. Setae very slender, forked, sigmoid, ^ith the teeth about 

 equal, like those of B. falciformis Bret., but numbering only 2 



June 19th, 1912 . x 



