13 
Genera, Same author. Journal of the Royal Microscopical 
Society, December, 1888. 
A Revision of the Genus Actinocyclus, Ehrenberg. Same author. 
Journal of the Quekett Microscopical Club, July, 1890. 
A Revision of the Genus Coscinodiscus, Ehrenberg, and of some 
allied Genera. Same author. Proceedings of the Royal 
Society of Edinburgh, Vol. xvi. 
Mr. Rattery is entitled to the everlasting gratitude of diato- 
mists for his extended labors in endeavoring to reduce to a sys- 
tem the classification of the many species included in the genera 
named. The artificial key appended to each will be found of 
especial value in tracing species. Most diatomists, however, will 
probably regret that the author did not do more in the way of 
condensing the number of species. 
Le Diatomiste. J. Tempére. Paris. 
This is a quarterly journal devoted to the Diatomacez. 
Three numbers have already appeared. Each number is accom- 
panied by two phototype plates. As Prof. Tempére is assisted 
by such well-known authorities as Messrs. Brun, Cleve, Grove — 
and Peragallo, it is likely that the character of the journal will be 
well sustained. 
In the number for June, 1890, M. Peragallo gives a tabular 
list of species of Coscinodiscus as given by Schmidt, Van Heurck 
and Castracane, and in parallel columns the synonyms according 
to Rattery. This table is of especial value, and will save the stu- 
dent much research. C. H. KAIN. 
Salvinia natans (L.) All., in Minnesota. 
This very interesting heterosporous pteridophyte is apparently 
rare in North America. It is reported in the fifth edition of Gray’s 
Manual as probably not occurring in North America, although 
Pursh is supposed to have found it in Western New York.. In 
the sixth edition this uncertainty is somewhat dispelled by a re- 
port of the plant from Missouri, but no authority is given for the 
Station. It is, therefore, an important discovery which this note 
chronicles, viz., that Sa/vinia natans (L.) All, grows in Swee- 
—ney’s Twin Lake, four miles west of the city of Minneapolis. — 
Only a few plants have been found and these have been trans- 
