yS Friend : Oligocliats of Great Britain and Ireland. 



setae in segments 2-6, numbering 3 per bundle, only 2 per bundle 

 from segment 7 backwards ; teeth equal, length of setae about 

 one-third diameter of body. Nerve ganglia greatly enlarged 

 in front. Near Smisby and Stretton-en-le-field, on the borders 

 of Derbyshire and Leicestershire. 



Limnodrilus trisetosits Friend. — Similar to the last. Setae 

 3 throughout ; in all other species the number is smaller in 

 posterior bundles than in anterior. Lower tooth somewhat 

 larger than upper. Chloragogen cells begin in 5. No penis 

 sheath yet found. Mud of the Thames, Tottenham. 



Limnodrilus galeritus Friend. — Setae 4 in ventral, 5 in dorsal 

 bundles in segments 2-7, then usually 3. Penis sheath about 

 15 times longer than broad. Setae one-sixth the length of 

 penis sheath. Characterised by the cap on the spermathecae 

 near the external aperture, whence the specific name. With 

 the last in mud at Tottenham. I must refer to the R.M.S. 

 paper for notes on some further species, such as L. Wordsworth- 

 ianus Friend, L. incequidens, etc. 



Rhyacodrilus falciformis Bret, (igoi ' Rev. Suisse de Zool.' 

 IX., 205= Ilyodrilus filiformis Dit., 1904, ' Zeit. Wissen. 

 Zool.,' Bd. yy, j^o?> =^ Meganympha pachydriloides Fr., see 

 ' Nature,' November i6th, 191 1, p. 78). Found in a little 

 stream at (i) Netherhall, near Bretby ; and (2), Netherseal, 

 near Ashby-de-la-Zouch. 



Spirosperma ferox Eisen. 

 Heterocha^ta costata Clap. 



,, thompsoni Southern. 



Psammoryctcs barbatns Grube. 

 Tubifcx tubifex Miiller. 



,, templetoni Southern. 



,, globulatus Friend. R.M.S. , 



December 20th, 191 1. 

 Hemitubife.x benedeni (--=benedii) 



ITdek. 

 Hemitubifex pustulatus Friend, 



1898 (' Zoologist,' Series IV., 



Vol. II., 119; regarded as a 



variety of H. benedeni, but now 

 held to be a new species). 

 Ilyodyilus {= Tubifex) campantda- 

 ttis Eisen. 



(=Tnbife x) bo )i neti 

 Clap. 



( = Mono pylephor lis) 

 tvichochaetus Dit. 

 Ilyodrilus coccineus Vejd. (=Bran- 

 chiura coccinea Vejd. of South- 

 ern's List). 

 Ilyodrilus robustus Friend. 

 ,, pallescens Friend. 



Details respecting Tubifex and Ilyodrilus, two of the most 

 difficult genera at present under review will be found in the 

 paper read December 20th, 191 1, before the Royal Micros- 

 copical Society. 



IV. LUMBRICULID/E. 



Lumbriculus variegatus Miiller. 

 Trichodrilus (Phreatothrix) canta- 

 brigiensis Bcddard. 



StylodriluH \ejdovskyi Benham. 

 ,, gabretae Vejd. 



,, hallissyi Southern. 



I leave this list untouched. A well-worm found at Milden- 

 hall, a Trichodrilus at Shrewsbury, a Stylodrilus collected in 

 Cumberland and Derbyshire, are as yet unrecorded. The 



Naturalist, 



