39 
22-35 /u long, densely reticulated, and usually with a few papiil©. 
Abundant on the muddy banks of the Pautuckaway river at 
Epping, N. H., and flats of the mill-pond of the same river; West 
Epping, associated with I. echinospora muricata, I. ech inospora ro~ 
busta, I. Eatoni, J. Engelmanni and I. Tuckermani , or often alone. 
A. A. Eaton. Flats at East Kingston, N. H , Dodge. Aug. 1896. 
V 
I. Eatoni Dodge, n sp. Amphibious; trunk very large, 
|-1£ inches in diameter ; bulb diameter sometimes 2§ inches. Ver- 
ual or subaqueous leaves sometimes 200, reaching the length of 
28 inches ; estival leaves much shorter, 3-6 inches ; stomata abun- 
dant ; peripheral bast-bundles irregular in occurrence ; sporangia 
large, pale spotted; macrospores small, 300-450 //in diameter, tet- 
rahedro-globose, their sculpture labyrinthiform- convolute ; micro- 
spores 25-30 //, smooth or slightly papillose. Plant polygamous. 
Vernal form the middle of July ; estival form Aug.-Sept. 
East Kingston, N. H., July, 1895, and Epping. N. H., August, 
1896, A A. Eaton. For detailed description with illustrations, see 
Botanical Gazette, January, 1897. 
241. I. Engelmanni A. Braun. Leaves 15-100, bright green, 
4-20 inches long, furnished with four peripheral bast-bundles ; 
stomata abundant ; sporangia unspotted ; velum narrow ; macro- 
spores clear white, 350-550 /z in diameter, delicately honeycomb- 
reticulated ; microspores light colored, 24-28 //, smooth or nearly 
so. 
This plant when growing in merely damp places, as is often 
the case, or in places where it is for the greater part of the time 
out of water, produces erect-spreading leaves 4-6 inches long. In 
situations subject to heavy inundations during the winter and the 
spring, .the leaves of early growth are much longer, at times reach- 
ing the length of 18 or 20 inches. As the water recedes the upper 
portion of the leaves floats on the surface. Finally the plants be- 
come nearly or quite emersed and the long leaves prostrate on the 
mud, decay and are succeeded by a shorter, nearly erect growth, 
