60 ISOfiTACEAE (QUILLWOET FAMILY') 



gynospores 488-720 /x (average 600 /x) in diameter, sparingly covered with thick 

 vermiform suboonfluent or reticulated ridges except just beneath the equator ; 

 androspores 31-44 /i (average 36 /i) long, verrucose. — Ponds 

 and lakes, N. S., Que., and Me. Fiu. 26. 



4. I. foveolata A. A. Eaton. Polygamous ; leaves 50-150, 

 5-15 cm. long, 2 mm. in diameter, round, pinkish or olive- 

 green ; sporangia thickly dark-spotted, ^\ covered by the 

 26. 1, hiei-oglyphica. ^^j^^ . gynogpores 380-560 /i (average 44J /j.) in diameter, 

 Cynospore X IS. ^^^ j^^^^ surface covered Vfith little holes, the upper a 

 little mortj open ; androspores 22-35 ^ long, reticulated or 

 papillose. — Ponds and river borders ; N. H. and Ct. Fig. 

 27. 

 _ _ Var. plen6spora A. A. Eaton. Leaves 30-110, 1.5 mm. 



2T I foveolata Gvno- in diameter, 20-40 cm. long ; sporangia thickly dark-spotted, 

 spore X 15 i-}- covered by the velum ; gynospores white or ashy, 450- 



600 n (average 610 /i) in diameter, covered with tall thin 

 mostly honeycomb-reticulated walls ; androspores 27-83 /i long, finely granular 

 or tuberculate. — Gravelly shores of ponds in a thin layer of silt, s. e. Mass. 



5. I. ripiria Engelm. Often polygamous; leaves 10-30, 1-3 mm. in diam- 

 eter, 10-25 era. long, erect, dark green ; sporangia densely spotted, J-| covered 

 by the velum ; gynospores 450-756 fi, (averaging 570 /i) in diameter, covered with 

 high isolated, united, or reticulated jagged crests ; androspores 28-32 /i (average 

 29 /ii) long, sparingly tubercled. — Tidal shores of Del. R., in gravel. — A species 

 misinterpreted in the past, and seemingly of restricted range. 



6. I. sacchar^ta Engelm. Leaves 10-30, 1-2.5 mm. in diameter, 3-25 cm. 

 long, spreading or recurved ; velum very narrow to half covering the thickly 

 spotted sporangium ; gynospores 420-510 /i (average 480 /j.) in diameter, covered 

 with low granules, reticulated walls or tall rough crests ; androspores 22-30 /i 

 (average 28 /u.) long, sparingly papillose. — Eresh-water tidal flats, n. arm of 

 Chesapeake Bay and Del. R. — Very variable and closely approaching the last in 

 some of its forms. 



Var. Amdsii A. A, Eaton. Trunks 2-5-lohed ; leaves 8-30 cm. long, 1-1.5 mm. 

 in diameter, slender, finely pointed, quadrangular ; sporangia with few spots, 

 ^f covered by the velum ; gynospores 420-600 /t (average 510 /i) in diameter, 

 marked with fine granules and tliin short often reticulated walls; androspores 

 28-32 /i long. — Gravelly shores overlaid by fine silt, chiefly in shallow water, 

 s. Mass. to N. Y. 



7. I. echin6spora Dur. Leaves 10-30, 5-15 cm. long, 1.5-2 mm. broad, 

 dark green, finely pointed ; velum about one half covering the sporangium ; 

 gynospores 350-560 fn (average 500 fi) In diameter, covered with simple or 

 forked spinules ; androspores 26-30 fi long, smooth. — Eu. — A species repre- 

 sented in America by the following varieties. 



Var. Braiinii (Dur.) Engelm. Differs from the type in having stomata on 

 the leaves, a broader velum, spotted sporangium, and not rarely broad jagged 

 crests on the gynospores. (Var. ro6?(si(jt Engelm. ; 7. Beottii 

 A. Br:) — Muddy or sandy river and pond borders, Gasp^ 

 Co., Que. to B. C., s. to Cal. and Pa. ; variable. EiG. 28. 



Var. muricata (Dur.) Engelm. Submersed leaves 10-30, 

 flaccid, spiral, 15-40 cm. long, 1 mm. in diameter; emersed og t v- 

 ones 5-8 cm. long, slender, recurved ; sporangia pale-spotted, ir^nnii ' GvMSDore 

 J-l indusiate ; gynospores 400-620 /j, (average 510 ;x) in x 15 " 

 diameter, covered with slender round spines and flat, blunt, 

 or retuse lamellae; androspores 25-31 /* long, smooth or slightly granular. — 

 Firm soil in shallow waters, mostly submersed ; N. S. to n. Me. and N. J. 

 — Grades into the last. 



8. I. Eatbni Dodge. Polygamous ; leaves 30-200, 40-70 cm. long, S-4 mm. 

 in diameter, flat above; stomata abundant; bast-bundles usually present; 

 velum very narrow ; sporangia densely light-brown spotted, not filled by spores ; 

 gynospores round below, upper half depressed, 300-450 fi (average 390 /<.) in 

 diameter, with labyrinthiform-oonvolute ridges ; androsporangia very rare, 



