JOURNAL 



OF THE 



KOYAL MICROSCOPICAL SOCIETY, 



DECEMBER. 1912. 



TRANSACTIONS OF THE SOCIETY. 



X. — British Enchytrseids. 

 By The Rev. Hilderic Friend, F.L.S., F.R.M.S. 



{Read November 20, 1912.) 



IV. The Genus Henlea. 



The Annelids, which I propose to study in this paper, are all 

 microscopic. Few reach the length of 20 mm. I do not know a 

 single species which exceeds that length when at rest, while several 

 are less than half an inch long, and one seems, normally, to measure 

 2-3 mm. I have, therefore, had to adopt special means for their 

 discovery, and in this I have been aided by a Government grant, 

 which has been generously renewed. I find about twenty-five 

 species in my most recently compiled list, a large proportion of 

 which are now known to be British, and this, in itself, is a striking 

 illustration of the progress which has been made in the study 

 during recent years. 



We shall the better realize this if, in the first place, we take 



I. — A Brief Historical Survey. 



The genus Henlea was created by Michaelsen in 1889 {!).* 

 The name is intended to do honour to Henle, an early authority in 

 zoology. How far it is in the best interests of science to adopt 

 such names, I need not here discuss. It suffices to say that the 

 name does not supply the least hint as to the characters by which 

 the genus is differentiated. Certain species of Enchytraeids, which 



* The figures iu brackets refer to the Bibliography at end of paper. 

 December 18th, 1912 2 R 



