362 TKANS. ST. LOUIS ACAD. SCIENCE. 



form of echhwspora^ either of which may be expected in those 

 regions. 



1843. Torrey, Flora of New York, ii. 514, "/. lacustris^' a 

 mere repetition of Pursh's statement. 



1844. Bory investigates the Genus, which until then had been very 

 much neglected, and adds to the three then known species (/. lacustrts, 

 Coromandelina, and setacea) three new ones discovered in Algeria by 

 Durieu de Maissonneuve. 



1846. A. Braun, in Regensburg bot. Zeitung, No. 12, briefly 

 characterizes /. r/^ar/a', Engehn., from Philadelphia; /. Engel- 

 fuanni^ A. Br., from Missouri, and I. Jiaccida^ Shuttlew., from 

 Florida. 



1847. The Amer. Journ. Arts & Sciences, n. ser. iii. 52, pub- 

 lishes a translation of the above notice. 



1845. A. Gray, in the flrst edition of the Manual Bot. North. 

 States, p. 640, distinguishes the then known three northern spe- 

 cies, /. lacustris, I. riparia, and /. Engelmanni. 



1853. Darlington, Fl. Cest. ed. ii. p. 402, mentions "/. lacus- 

 trts" as growing in shallow ponds in his district. This must refer 

 to /. E?tgelmanni, the only species growing there in such lo- 

 calities. 



1856. A. Gray, Manual, ed. ii., gives an almost verbal reprint 

 of the first edition. 



i860. Chapman, Fl. South. States, p. 602, describes /. Jlac- 

 cida as growing in "lakes and clear streams" in Middle and West 

 Florida. 



In the same year E. Tatnall, Cat. PI. Newcastle Co., Delaware, 

 enumerates /. riparia and /. Eizgelmanni^ both of which names 

 here probably stand for the latter. 



1861. Durieu de Maisonneuve, Prof, of Botany at Bordeaux, in Bull. 

 Soc. Bot. France, viii. p. 164, distinguishes and characterizes the two 

 North European species /. lacustrts and /. echinospora, heretofore thrown 

 together. 



1S64. The same author, 1. c. loi, 102, indicates four Ameri- 

 can Isoetes: muricata from Massachusetts, Braunii ixovsx New 

 Hampshire, macrospora from the Catskill Mountains, and mela- 

 nopoda Gay (or Gay and Durieu) from Illinois. 



In the same year A. Braun published a most important treatise on the- 

 Genus in his account of the Isoetes of the Island of Sardinia, in which our 

 species are frequently referred to. 



