PROCEEDINGS OF THE SOCIETY. 417 



As regards the number of species of British fresh-water Copepods, 

 there were about ten species of Diaptomus and two of the allied genus 

 Eurytemora. Cyclops was represented by at least twenty-five, perhaps 

 thirty, species. Of Canthocamptus, Nitocra, Moraria, and other genera 

 belonging to the Harpacticidas there were some twenty-five species, but 

 there was yet much work to be done on this group. 



In the determination of the species of Copepods very minute char- 

 acters were relied upon as a rule, but strangely enough some closely 

 allied species showed characteristic colour markings and other peculiarities 

 which could be seen by the naked eye or a pocket-lens. Some of these 

 characters had been used long ago by Koch, a copy of whose work had 

 been very kindly brought to the meeting by Mr. Soar. 



For the examination of Copepods, the Rousselet live-box was pro- 

 bably the best method, especially when fitted with a thin metal ring 

 to which very thin cover-glasses could be cemented. By this means the 

 highest powers could if necessary be brought to bear on the object. 

 When so used in conjunction with a good condenser details of structure 

 could usually be made out which would only otherwise be obtainable by 

 dissection, a troublesome matter when dealing with creatures no more 

 than sV-iw- perhaps. For preserving in tubes formalin was probably the 

 best all-round medium, and for mounts glycerin-jelly was on" the 

 whole most suitable. 



Mr. Scourfield then referred briefly to some of the actual specimens 

 exhibited. 



The following' objects (Fresh-water Copepods) were exhibited: — 



Mr. S. E. Akehurst . Diap)tomus castor 6 . 



Mr. E. Cuzner . . . Cyclops fuscus, etc. 



Mr. D. Davies . . . C. strenuus. 



Miss L. R. Francis . . C. phnleratiis. 



Mr. J. Grundy . . . C.fiiscus 9. 



Dr. J. R. Leeson . . Canthocamptus mimdus. 



Mr. J. M. Oflford . . Cyclops vicinus. 



Mr. R. Paulson . . . C. hicolor, the smallest British species 



of Cyclops. 



Mr. F. J. W. Plaskitt . Diaptomus castor 9 . 



Mr. J. Richardson . . Cyclops macrurus. 



Mr. D. J. Scourfield. . Viguierella cceca {Belisarius viguieri), 



from the cups formed by the leaves 

 of P>romeliaceous plants at the 

 Royal Botanic Gardens. Moraria 

 arboricola, from tree-holes in 

 Popping Forest. 



Mr. C. J. TI. Sidwell . Cyclops fiiscus 6 . 



Mr. C. D. Soar . . . Canthocamptus minutus. 



Mr. W. R. Traviss . , Cyclops affinis. 



Mr. J. Wilson . . . Cyclops albidus. 



A vote of thanks was accorded to Mr. Scourfield and to those who 

 |md brought microscopes and specimens. 



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