JUNGERMANNIACE^E. (SCALE-MOSSES.) 725 



* * Hairy on the margins and midrib beneath, smooth above ; dioecious (n. 4 



monoecious). 



2. M. myri6poda, Lindb. Thallus elongated (2' long, \" wide), dichot- 

 omous, the long linear branches of uniform width, convex above, the reflexed 

 margins not undulate; midrib densely pilose beneath; hairs rather long, 

 straight or nodding, the marginal mostly in clusters of 3-6, some with dis- 

 coid tips ; midrib covered above with 2 rows of enlarged cells, and beneath 

 with 3-7 (usually 4-6) rows of smaller cells, lax and often indistinct. (M. 

 furcata, Sulliv., in part; not Nees.) Shaded rocks and trees in the Alle- 

 ghanies (Sullivant), and southward. 



3. M. hamata, Lindb. Like the last ; thallus much elongated (4' long, 

 1 - l" wide) ; hairs very long, divaricate and hooked-deflexed, the marginal 

 in twos, rarely with discoid tips ; midrib covered above and below with two 

 rows of enlarged lax cells. (M. furcata, Sulliv. , in part.) AUeghany Mts. 

 (Sullivant). 



4. M. conjugata, Lindb, Thallus 1^' long, ^-1" wide, usually dichoto- 

 mous, the short branches irregular in width, convex above, the margins more 

 or less undulate ; hairs rather long, straight, divaricate, the marginal usually 

 in twos, very often disk-bearing ; midribs covered above with 2, below with 

 3-6 rows of enlarged lax cells. On shaded rocks and trunks of trees, central 

 N. Y., and southward. (Eu.) 



33. ANEURA, Dumort. (PI. 23.) 



Thallus fleshy, prostrate or assurgent from a creeping base ; costa obscure. 

 Dioecious or monoecious. Fructification arising from the under side near 

 the margin. Involucre cup-shaped, short and lacerate, or none. Calyptra 

 large, fleshy, more or less clavate. Capsule large, oblong-cylindric. Elaters 

 unispiral, in part adherent to the tips of the valves. Spores minute, smooth 

 or minutely roughened. Antheridia immersed in the surface of receptacles 

 proceeding from the margin of the thallus. (Name from a- privative, and 

 vtvpajs, a nerve.) 



* Thallus narrow (about 1" wide), palmately divided. 



1. A. latifrons, Lindb. Thallus cespitose, ascending or erect, usually 

 dark green, 6 - 9" long, mostly pellucid ; branches linear, obtuse and emargi- 

 nate, plano-convex ; cells large, oblong-rhombic ; monoecious ; archegonia 3 - 

 10, short, conic; calyptra white, verrucose, pyrif orm-clavate ; capsule ovali 

 brown; spores 12J-14-J- /i broad, globose, minutely and densely papillose*/ 

 antheridia globose. (A. palmata of authors ; not Dumort.) On rotten logs ; 

 common. 



* * Thallus narrow (about \" wide) y pinnate or bipinnate. 



2. A. multifida, Dumort. Thallus prostrate, brownish-green, pinnately 

 divided, the primary portion biconvex, somewhat rigid, the branches horizontal, 

 pectinately pinnate with narrow linear divisions ; monoecious ; fructification 

 rising from the primary part or from the branches ; involucre fleshy ; calyptra 

 tuberculate. Var. M\JOR, Nees. Primary portion and branches thick, the 

 branches interruptedly pinnate with short obtuse divisions. On decayed 

 wood and moss in swamps, N. J. (Austin), and south in the mountains. (Eu.) 



