439 



PROCEEDINGS 



OF THE 

 QUEKETT MiCROSCOPlCAL CLUB. 



At the 533rd Ordinary Meeting of the Club, held on April 9th, 

 1918, the President, Dr. A. B. Rendle, M.A., F.R.S., F.L.S., in 

 the chair, the minutes of the meeting held on March 12th were 

 read and confirmed. 



Messrs. Wm. Moore Tipping, A. Harry Matthews Fox and 

 Ernest J. Vickery were balloted for and duly elected members 

 of the Club ; nomination forms were read on behalf of two for 

 the fii"st time. 



The Secretary announced that the first excursion of the Club 

 would be to the Royal Botanic Gardens, Regent's Park, on 

 Saturday, April 13th, that there would be a Gossip Meeting on 

 the 23rd inst., and that at the next Ordinary Meeting on May Mth 

 Mr. F. Martin Duncan would give an address on "Insects as 

 Transmitting Agents of Disease," illustrated by lantern slides 

 and prepared specimens. 



The President then called upon Sir Nicholas Yermoloff, K.C.B., 

 to read his paper on " Some Intermediate Forms of the Genera 

 Navicula and Cymbella." 



Sir Nicholas said : — All students of Diatomology are invariably 

 impressed by the immense number of forms, species, subspecies 

 and varieties described, named and classified. The differences 

 which have led to the creation of new forms are sometimes very 

 trifling and uncertain, based upon personal impressions of ob- 

 servers, and consequently a maze of confused synonymy has 

 arisen. From time to time various distinguished authors have 

 tried to remedy this state of things, striving to reduce the existing 

 number of admitted species and varieties. Such regroupings 

 have been attempted by Cleve as regards the genus Navicula, 

 by Cox and Rattray as regards Coscinodiscus. One such writer 



JouRN. Q. Ivl. C, Series II.—No. 83. 33 



