pe0ceeding8 of societies. 147 



Eeadikg Microscopical Society.* 



October lOth, 1871. — Captaiai Lang presided, and, after the usual 

 business, read a short paper entitled " Another Hint on Selecting and 

 Mounting Diatoms," in which he more particularly described a 

 method, devised and adoi)ted by Mr. Tatem, for obtaining separate 

 diatoms from balsam-mounted slides. Specimens of diatoms taken 

 from old slides and remoimted were shown as illustrations of results. 



He also exhibited a new form of wooden slide, with sunk cell, for 

 opaque objects. This was obtained from Mr. Crouch, of London Wall. 



Mr. Tatem exhibited arranged mounts of diatoms obtained from 

 mixed and dirty balsam-mounted slides, and also specimens of Difflugia 

 spiralis. 



Mr. Austin exhibited as s^^ecimens of microscopic fungi, Miicor 

 ramosuvi, Phragmidimn obtusum, Puccinia syndenesiarum, &c. 



Mr. G. Davies exhibited Moller's type slide. 



November 7th, 1871. — Mr. Tatem contributed a short paper " On 

 the Conjugation of Amoeba" which appears in this Journal. 



Captain Lang exhibited twelve slides of diatoms, each containing a 

 separate species, shown in its two principal aspects of front and side 

 views. The genera and species were Biddulphia aurita, B. Tromeyi, 

 B. pidcliella, GompJionema geminatum, Triceratium favus, Melosira are- 

 naria, Navicula clejysydra, Pinnularia lata, P. alpina, Campylodiscus 

 costatus, Surirella splendida. 



Mr. Tatem exhibited diatoms from Eio Janeiro and Puerta Segura. 



December 5th, 1871. — Captain Lang exhibited, mounted side by 

 side, on the same slide, the two valves of an entire frustule of Surirella 

 fastuosa, picked from Singapore shell cleanings, and separated from 

 each other under the microscope. He drew attention to the great 

 dissimilarity of the two valves, the median space of the one being 

 broadly lanceolate, whilst that of its fellow is linearly lanceolate ; 

 the costfe of one valve being, of course, proportionately shorter than 

 those of the other, for he does not consider the irregular markings 

 within the median space to be in either case the continued costse, 

 though Dr. Greville has described them as such. They appear to him 

 entirely disconnected. 



It has long been a well-known fact that the upper and lower 

 valves of certain diatoms, as J.c7man</jes and Cocconeis,ave not identical 

 in structure, but he is not aware that this has been found to be the 

 case in any of the very numerous species of Surirella. 



Mr. Kitton, in his controversy with the Eev. E, O. Meara in the 

 ' Quarterly Jom-nal of Microscopical Science,' vol. viii., N.S., justly 

 remarks upon the great difference in the size, outline, and striation of 

 this particular species, but does not allude to the diversity in the 

 valves of the same frustule. 



Captain Lang also exhibited wings and elytra of rare butterflies 

 and beetles from Brazil, sent to him by Captain Perry. 



Mr. Tatem exhibited mounted diatoms, and Mr. Austin small 

 fungi and mounted desmids. 



* Eeport furnished by Mr. B. J. Austin. 



