164 PROCEEDINGS OF SOCIETIES. 
Presented by 
The Foot of the Fly, its structure and action ; elucidated 
by comparison with the Feet of other Insects, &c., 
Part I, by Tuffen West, Esq. . . The Author, 
On some Conditions of the Cell-wall in the Petals of 
Flowers, with remarks on some so-called External 
Secondary Deposits, by Tuffen West, Esq. . Ditto. 
Remarks on some Diatomaceze new or imperfectly 
described, anda new Desmiz, by Tuffen West, Esq. Ditto. 
Journal of the Proceedings of the Linnean Society, Vol. 
8, No. 30. . The Society. 
The Aunals and Magazine of Natural History, Nos. 84 
and 86. Purchased. 
March 8th. 
Quarterly Journal of the Geological Society, No. 81 . The Society. 
Journal of the Linnean Society, No. 32 4 . Ditto. 
Intellectual Observer, No. 38 ; t . The Editor. 
Photographic Journal, No. 154. Ditto. 
On extreme and exceptional Variation of Diatoms in 
some White Mountain Localities. &c., by Dr. F. W. 
Lewis. The Author. 
A Treatise on Logic, pure and applied, by 8. H. Emmens, 
Esq. ‘ : Ditto. 
W.G Sauneien Curuior. 
Dusiin Microscorrcan Cuves. 
17th November, 1864. 
Reap the mimutes of the preceding evening meeting, which were 
passed and signed. 
Dr. Frazer exhibited crystals of the rare urinary deposit “ eys- 
tine,” in process of crystallizing from an alkaline fluid. 
Mr. Archer showed a minute Rivulariacious plant from the Chalk 
in the south of England, kindly given to him by Admiral Jones. 
This plant he felt unable to refer to any of Kiitzing’s genera, at 
least satisfactorily. The “pbhycoma” (to employ Kiitzing’s term} 
consisted of an aggregation of filaments radiately disposed, and, 
to the naked eye, forming orbicular dots, like so many “ full stops,” 
and seated in little concave depressions, as if excavated by the 
pau in the Chalk. The individual filaments were minute, slightly 
tapering, with a single basal heterocyst, extremities not attenu- 
ated, ieimeaee! the tubes not closed. If one did not know the 
plant in the Chalk, Mr. Archer said that, meeting a single fila- 
ment, it might be taken for Kiitzing’s Mastichonema cespitosum, 
