372 British Hydrachnidce : The Genus Fiona. [Sess. 



among the semi - parasitic Copepoda of Scotland, not to 

 speak of the British Islands, our knowledge of them is 

 being gradually added to, and ere long, instead of forming 

 a small portion of a general monograph, they may require 

 a monograpli all to themselves. 



At this meeting Mr T. Cuthbert Day gave a very interest- 

 ing and instructive Lantern Demonstration on " Colour and 

 Colour Photography," which was greatly appreciated by the 

 members. 



At the meeting of the Society, held on March 27, 1907, 

 Dr Watson communicated a paper, entitled " Notes on Ac- 

 climatised Plants," by Mr William Wilson of Alford, Aber- 

 deenshire. At the same meeting Mr Symington Grieve, under 

 the title of "A Field Naturalist's Eamble in Martinique and 

 Dominica," gave an extremely interesting account of his recent 

 visit to the West Indies. This paper was illustrated by a 

 large number of lantern slides from photographs taken during 

 Mr Grieve's visit. 



Nl.— BRITISH HYDRAGHNID^ : THE 

 GENUS FIONA. 



Bt Mr CHAS. D. SOAE, F.E.M.S., Corresponding Member. 

 {Read April 21t, 1907.) 



There is a difference of opinion amongst writers on the 

 Hydrachnidse in regard to the correct name of this genus. 

 It was called Nesaea by Koch in 1842, and for a long time all 

 the species were arranged under that generic name. It was, 

 however, afterwards found that the name Nessea had already 

 been used by Lamarck in 1812 for a genus of Polypes. Never- 

 theless, the name Nesaea continued to be used by all the 

 writers on water- mites until 1891, when Dr Koenike of 



