268 l'KOCEEDINGS OF THE SOCIETY. 



MEETING 



Held on the 18th of March, 1908, at 20 Hanover Square, W. 

 The Right Hon. Lord Avebury, F.R.S., etc., President, 



in the Chair. 



The Minutes of the Meeting of the 19th of February, 1908, were 

 read and confirmed. 



The following Donation to the Society was announced, and the 

 thanks of the Meeting were voted to the donor. 



From 

 Woodward, Horace B., History of the Geological Society of ( afrf^aTRnkptv 

 London (8vo, London, 1907) {^f London V 



Mr. J. Ciceri Smith read a description of a direct-reading micro- 

 meter gauge, which he exhibited in the room ; the mechanism of the 

 instrument being further illustrated by diagrams. 



Mr. Smith said this micrometer would be found very convenient for 

 rnicroscopists. It was an improved cover-glass gauge, with an auto- 

 matic calculating index, upon which the thickness of the glass in decimal 

 fractions of an inch was seen at a glance, and upon the divided-thimble 

 half divisions ( = iroV o m could be read off. A full description of the 

 instrument, with illustrations, will be published in next issue. 



The thanks of the Society were unanimously voted to Mr. Smith for 

 his exhibition and explanation. 



Mr. C. F. Rousselet gave the following account of a series of mounted 

 specimens of the rarer species of fresh-water Polyzoa, which were ex- 

 hibited under Microscopes in the room. 



The fresh-water Polyzoa received a good deal of attention from 

 zoologists about the middle of last century, but Professor xAJlman, by 

 the publication in 1856 of his monograph of this group, appears to have 

 almost exhausted the subject as far as Great Britain is concerned, for 

 during fifty years afterwards no new species were discovered in England, 

 with the single exception of the remarkable Victorella pavida, found by 

 Saville Kent in 1868. 



Naturalists abroad, in America, Germany, India, Japan, etc., have 

 been more active, and have brought to light about a dozen new species 

 of great interest, and it is these rarer and mostly foreign forms which 

 my exhibit this evening is intended to illustrate. 



The well-known and common species, such as Lophopus, Cristatella, 

 Plumatella, Fredericella sultana, and Paludicella, have often been ex- 

 hibited, and are not here this evening. The forms represented are the 

 following : — 



1. Victorella pavida Saville Kent was first found at one of the earliest 

 excursions of the Quekett Microscopical Club, on September 12. 1868, in 

 the Victoria Docks. Some years afterwards, in 1885, it was found 

 again by Dr. Bousfield, in the Surrey Canal, and in March 1906, guided 



