HepaficfP of Norfh America. 75 



2. M. thuja Duiiiort. ir^tems creeping, sparingly 

 branched, simply pinnate; branches short; leaves fuscous- 

 green, closely imbricate; upper lobe strongly incurved, obtuse 

 with the apex mucronulate or 2-4-denticulate; lower lobe ob- 

 long, somewhat acute, repand and somewhat denticulate; am- 

 })liigastria liroadly ovate, reflexed-spreading, subentire. (Jiin- 

 (/cniiaii/a thuja Dicks.) 



ITah.—lW. {Wolf). (Eu.) 

 5i/>.— Hep. Europ. p. 24. 



8. M. Sullivanti Aust. Stems mostly simply pinnate, 

 the apex strongly decurved in drying; leaves somewhat erect, 

 the ventral margin close, strongly involute toward the apex; 

 cells large punctate-stelliform; inner involucre broadly carinate 

 beneath, the carina biangular; otherwise near M. inrolufa 

 Hampe. 



JTab. — Alleghany Mts. {SuMrant). 

 Bib.— Torvey Bull. Ill, 15. 

 Emc.—JleY). Bor.-Amet. No. 94. 



ff SfeDi'S sonieirJiaf hi-tri pinnate. 

 X Loirer lohe of leaves iiarron\ orate-JanceoJate. 



4. M. involuta Hampe. Stems irregularly pinnatel}^ 

 decompound; leaves closely imbricate, subrotund, deflexed, re- 

 pand or entire, the ventral margin slightly involute, the l)ase 

 decurrent, the lobe narrow; amphigastria approximate, quad- 

 rate-ligulate, entire. 



Ilah. — Banks of rivers, So. States {Lesqiierenx, Beyrich). 



Bib.— Syn. Hep. p. 282. 



Exsic- — Hep. Bor.-Amer. No. 93. 



XX Loivei- lohe of leaves broader. 



5. M. platyphylla Dumort. Stems irregularly bipin- 

 nate: upper lobe of leaf roundish-ovate, the basal margin more 

 or less undulate; the inferior lobes smaller, obliquely oval or 

 subrotund. the margins deflexed: amphigastria round-obovate 

 with reflexed margins, subentire; involucral leaves denticulate 

 or entire; mouth of inner involucre nearly entire. ( Jumjer- 

 inania platijplnjUa L., Lejeunia. platijplipUa Corda. ) A variety 

 is Jioif/erntatiia platyphijUoidea Schwein., (Madotheca platij- 

 phijlloidea Dumort.), (Austiit). 



