330 



The thanks of the Club were accorded to Mr. Nelson for his 

 interesting paper, and to Mr. C. Lees Curties and Mr. Traviss 

 for the apparatus exhibited. 



Owing to the number of papers on the agenda and the lateness 

 of the hour, a note on " Some New Diatomic Structure discovered 

 with a New Zeiss Apochromat," communicated by Mr. A. A. C. 

 Eliot Merlin, F.R.M.S., was taken as read. 



Mr. A. M. Jones said that at a recent meeting of the Royal 

 Photographic Society, Mr. Max Poser, of Messrs. Carl Zeiss's 

 London house, had stated that the objective referred to by Mr. 

 Merlin was not constructed to a new formula, but was a picked 

 one of the old series. 



Mr. James Murray, F.P.S.E., F.L.S., made some introductory 

 remarks to a paper he had contributed on '' Water-Bears, or 

 Tardigrada." The first notice in English of water- bears was in 

 1834 by Pritchard, of specimens found by Powell in Regent's Park. 

 There have been many changes in the names of water-bears. 

 They have now even lost the name Tardigrada, as that is 

 already appropriated by vertebrates. The present official name of 

 the group is order Arctiscoida, family Xenomorphidae. Mr. Murray 

 said that his paper was intended to supplement the one contri- 

 buted in 1907. Since that time considerable progress had been 

 made in the knowledge of water-bears. A great many species 

 have been discovered, and several new genera have been described 

 most of which are marine. The new genera are Tetrakentron, 

 Cuenot, 1892; Jlcdechiniscas, Richters, 1908; JJatillipes, Richters, 

 1909; and Oreella, Murray, 1910. 



Water-bears must no longer be regarded as a group as cosmo- 

 politan as are the Rotifers. Recent researches have shown that 

 half the known species are restricted to one locality, and about 

 three-quarters to one country, and only about a dozen species are 

 really cosmopolitan. 



The paper went on to describe at some length the relationships 

 of the various genera, and concluded with a synopsis of the ten 

 genera known, and the 120 at present admitted species. A 

 bibliography is appended. 



A cordial vote of thanks was unanimously voted to Mr. Murray 

 for his paper. 



Mr. M. Ainslie exhibited and described a " finder " for the 

 microscope useful with powers up to about jy in. It would fit 



