168 ALFRED GIBBS BOURNE. 



On Haplobranchus, a New Genus of Capito- 

 branchiate Annelids. 



By 



Alfred Gibbs Bourne, B.Sc. liond.. 



University Sciiolar in Zoology, Assistant in the Zoological Laboratory of 

 University College, London. 



With Plate IX. 



Occurrence. — This very interesting worm was kindly placed 

 in my hands for description by Professor Lankester, who 

 received it last November in quantity from Mr. Thomas 

 Bolton^ F.R.M.S., of Birmingham, accompanied by a sketch of 

 the animal in its tube, which I have reproduced in a modified 

 form in fig. 1. Respecting its habitat, I may quote the words 

 of Mr. W. H. Shrubsoll, who writes as follows : — 



*'The worms have been familiar to me for a long time, and 

 occasionally I have met with them in great abundance on the 

 coast of Sheppey. Not having books of reference at command 

 I had no means of knowing whether they were described or 

 not, and I assumed that they were. 



" As far as my experience goes, they are always found asso- 

 ciated with diatoms on the surface of soft mud at the bottom 

 of gullies, and the presence of the diatoms insures to the ani- 

 mal a plentiful supply of oxygen. 



"^ There is generally an inch or so of water overlying the 

 mud, and the diatomaceous film at the bottom is ornamented 

 with silvery-looking globules of oxygen. 



''As it is impossible to collect either the diatoms or the 



