112 Illinois State Laboratory of Natural History. 



2. P. undata Sulliv. Like No. 1 but more rigid, with 

 simple branches; leaves horizontal, triangular-ovate, obtuse, 

 emarginate, or sparingly dentate at the apex, the dorsal mar- 

 gins reflexed and entire, the ventral repand-undulate ; amphi- 

 gastria 2-cleft, the segments dentate. 



Hdb. Shaded banks of rivers and wet rocks, Ga. (Suldvant, Les- 

 quereux). 



Bib.Syn. Hep. p. 659 ; Amer. Jour. Sci. and Arts, 1846, p. 73. 

 Exsic. Muse. Alleghan. No. 222 ; Hep. Bor.-Amer. No. 10. 



** Under side of stems without crestlike lines. 

 f Amphigastria 2-3-cleft, fugacious. 



3. P. porelloides Lindenb. Stems divided, the branches 

 ascending; leaves somewhat imbricate, convex-gibbous, obovate- 

 rotund, those near the summit of the stem repand-denticulate, 

 the others entire, the dorsal margin reflexed; inner involucre 

 terminal, oblong-ovate, the mouth compressed, denticulate. 

 (Jungermania viticulosa Schwein.) A variety is P. nodosa } 

 Tayl.' 



Hdb. Among mosses in swamps and rivers ; coramon. The var. in 

 mountain ravines, Canada, N. Eng , N. J. (Austin). 

 Bib.Syn.. Hep. p. 48, 645. 

 Exsic. Muse. Alleghan. No. 220 ; Hep. Bor.-Amer. No. 7, 7b. 



4. P. interrupta Dumort. Stems prostrate, copiously 

 rooting, branched, the branches horizontal; leaves imbricate, 

 oval, horizontal, entire or slightly repand; amphigastria lance- 

 olate, 2-3-cleft; inner involucre terminal, broadly obconic, the 

 mouth compressed, repand-crenulate. (P. macrostoma Sulliv., 

 Jungermania interrupta Nees.) 



Hdb. On moist banks and decayed logs; O. (Sullivant), N. Eng. 

 (Oakes), Greenland ( VaM). (Eu.) 



Bib.Syn. Hep. p. 48, 659; Hep. Europ. p. 44; Sulliv. Mosses U. S. 

 p. 96; Torrey Bull. VI, 85. 



DeUn. Sulliv. Mosses U. S. t. VIII. 



Exsic. Muse. Alleghan No. 221; Hep. Bor.-Amer. No. 6. 



ff Amphigastria wanting. 



