HepnticfP of North A ut erica. 25 



Hah. — Rocky ground ; N. Y. ( Torrey), Chester, Pa. {Porter), Cal. 

 [Bolander). (Eu.) 



Bib. — Syn. Hep. p. 605, Hep. Europ. p. 170. 

 Delin. — Lindenberg ]Monog. Ric. t. XXIX. 

 Exsic. — Hep. Bor.-Amer. No. 140 h. 



*** ThaUus more or less rilinfe on tlie margins, naked or obso- 

 letelij squdinons aJoiKj the extreme edge underneath; usually 

 nu'fli a pnrple spot in, tJie epidermis immediafeh/ over the 

 frnit. 



10. R. arvensis Aust. ThaUus always orbicular, radi- 

 ately much divided, 0.() — 1.8 cm. in diameter, dull gree}t hotJi 

 sides, papillose-reticulate and becoming fuscous above; margins 

 plane, entire, acute or apparently thickened, becoming purple 

 by age; divisions often crowded, somewhat dilated above from 

 a common base, dichotoraous, distinctly sulcate, carinate-thick- 

 ened especially toward the ajjex, nodulose beneath; lobes linear- 

 elliptic or subspatulate, acutisJi and ohsoletehj emarginate at the 

 apex; cilia white, very short or often papilla-like and incon- 

 spicuous; fruit aggregated beneath the canal chiefly toward the 

 apex of the lobes; spores about 0.071 — 0.084 mm. in diameter, 

 dark fuscous, slightly pellucid, distinctly reticulate, with a con- 

 spicuous pellucid margin. 



Var. hirta Aust. Thallus decidedly ciliate on the margin, 

 and with spine-like hairs scattered over the whole upper sur- 

 face, at length purple and more or less squamigerous beneath, 

 somewhat glaucous and reticulate above: divisions broader, 

 more obtuse, becoming thin and strongly canaliculate or often 

 convolute on drying; spores nearly black, larger, 0.084 — 0.101 

 mm. in diameter, opaque, very indistinctly reticulate, and ob- 

 scurely papillose, obscurely if at all margined. 



Hah- — Rocky ground and cultivated 'fields; Closter, N. J. {Austin). 

 The var. in similar locations. 



ifib.— Pro. Phil. Acad. 1869, p. 232. 

 Exsic. — Hep. Bor.-Amer. Nos. 141, 142. 



11. R. Lescuriana Aust. Monoecious; thallus stellately 

 or somewhat cruciately divided; divisions bilobed or di-trichot- 

 omous, obcordate or cuneate-linear, 0.4 — 1.3 cm. long, punctate- 

 reticulate, somewhat glaucous or cinereous green and slightly 



