34 
IsbETES L Qtjillwobt. 
Characters the same as in the order 
/ 
I. echinospora. This European species as founded by Du- 
rieu, has the following characteristics : Leaves 10-40, green or 
reddish at base, gradually tapering to a very slender elongated 
point ; stomata altogether absent ; sporangia unspotted ; velum 
very narrow ; macrospores nearly as in var. Braunii ; microspores 
a little smaller. Abundant in northern Europe, extending into 
Iceland, but as yet not noticed in America. 
Illustrated with full dissections by Motelay. 
233. I. echinospora Braunii Engelm. Leaves 10-30, green 
or reddish at base, erect, spreading, 2-10 inches long, a few sto- 
mata at their tips only ; peripheral bast-bundles absent ; sporangia 
pale-spotted ; velum about one-half indusiate ; macrospores 350- 
650 // in diameter, covered with broad spinules which are often 
forked or dentate, and at times confluent ; microspores 26-30 /y 
long, white or with a grayish tint ; smooth. 
Margins of ponds, often wholly submerged ; also on the muddy 
shores of streams, or on the tidal tracts of rivers, often where the 
water is very brackish, as in the Penobscot, Kennebec and Merri- 
mac. Common throughout New England. Late August. 
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234. I. echinospora robusta Engelm. Much stouter than 
the preceding; leaves 25-70, 5-8 inches long with abundant stoma- 
ta on the whole surface ; sporangia larger ; otherwise not differing. 
Type locality north end of Isle LaMotte in Lake Champlain, 
Pringle. Plants collected at Epping, N. H., on the Pautuckaway 
river by Mr. A. A. Eaton are similar in all respects to the type 
specimens. 
235. I echinospora Bootii Engelm. Leaves 10-20, slender, 
4-10 inches long, erect when short, bright green, with a few sto- 
mata near the tip ; macrospores with long, slender, simple spinules ; 
otherwise like var. Brawnii, 
