ON THE STRUCTURE OF VERMIOULUS PTLOSUS. 253 



On the Structure of Vermiculus pilosus. 



By 



E. S. Ooodrich, F.L..S,, 



Assistant to the Liuacre Professor, Oxford. 



With Plates 26—28. 



In 1892 (3a) I published a short description of an interesting 

 new Oligochsete I had found on the sea-shore near Weymouth. 

 Since then I have obtained more material, which I have worked 

 at in Professor Lankester^s laboratory at Oxford, and am now 

 able to give a more complete and accurate account of its 

 anatomy. 



The worm, which I have called Vermiculus pilosus, was 

 discovered in the rich black mud underlying the sandy surface 

 of the shore about halfway between Weymouth and Portland. 

 It lives there in considerable numbers with various species of 

 Pachydrilus and Tubificids, especially Heterochseta cos- 

 tata, Clap., from which it is quite indistinguishable to the 

 naked eye. Unlike the Enchytrseids, it does not seem to 

 venture to the surface amongst the decaying seaweed and in 

 the tidal pools, nor is it so often found underneath large half- 

 buried stones as other Tubificids, Heterochseta for example. 

 Fig. 1 represents it natural size ; it is from about 4 to 6 cm. 

 long, and of a dull reddish tinge. The body is soft, and its 

 movements are slow. Under a low power of the microscope 

 it can be distinguished at once, after a little practice, being 

 much less transparent than any of its associates. This opaque- 

 ness, caused chiefly by the structure of the body-wall, the 

 network of blood-vessels, and the enormous number of coelomic 



