40 
the earlier leaves of which often mature their sporangia before the 
close of the season. It is only in situations where the plants are 
thus alternately submersed and emersed that they attain a good 
development of leaves and trunk. 
This is probably the life history of all the amphibious species 
of Isoetes, as I. Eatoni, I. foveolata, etc., excepting those, which, 
like J. riparia and I. saccharata, grow under the influence of tide 
water. 
Connecticut — Meriden, F. W. Hall ; Waterford, C. B. Graves 
Rhode Island — Newport, W. G. Farlow. Massachusetts — Amherst, 
Prof. Tuckerman. Maine — M. L. Fernald. Abundant in eastern 
Massachusetts. Probably throughout our range, but reported 
principally from near the coast. In ditches, brooks and slow run- 
ning streams, usually in clayey soil. 
Illustrated with full dissections by Motelay. 
241 . 1 . I. Engel manni gracilis Engelm. A form with a few (8- 
12) very slender leaves, 9-12 inches long. Bast-bundles weak or 
but two or three of them. In deep water or often in shaded locali- 
ties. As all the species of this group attain their largest growth by 
abundance of sunlight, I. Engelmanni indeed requiring to become 
terrestiai or nearly so for a portion of the time, it is probable that 
the form gracilis is one of arrested development. 
Westville, Conn., Setchell. Brattleboro, Vt., Frost. Newport, 
R. I., D. C. Eaton. Hampton Falls, N. H , River Parker, Newbury, 
Mass., R. D. South Hampton, N. H., A. A. Eaton 
LITERATURE. 
Baker’s “Fern Allies,” London, 1887, contains descriptions of 
all species recognized at the time of publication. 
Britton & Brown’s “Illustrated Flora of the Northern United 
States and Canada,” contains illustrations of all the Fern Allies 
