Hepaticce of North America. 77 



( J. M. Bolanderi Aust, Stems short, tumid; subflexu- 

 ous, slightly twisted, nearly simple; leaves densely imbricate, 

 dimidiate-ovate or oblong, widely spreading, nearly plane, the 

 margin repand or in places caudato-dentate; the lobe almost 

 separate, small, lanceolate-siibulate, falcate, twisted, canalicu- 

 late, obtuse or acute, repand-undulate at the margin, sparingly 

 caudate at the base; amphigastria scarcely wider than the stem, 

 lingulate-ovate or oblong, obtuse or acute, the margins long 

 decurrent, repand-undulate, caudate-lacinulate; inner involucre 

 large, sharply 2-keeled or somewhat winged beneath, indis- 

 tinctly nerved above; lower lobe of the involucral leaves acute, 

 acuminate; capsule oval. 



Hob. Cal. (Bolander). 

 Sib.Torrey Bull. Ill, 14. 



XL RADULA NEES. 



Sporogonium terminal on short branches or in a fork. 

 Inner involucre compressed or nearly terete, truncate, entire, 

 the mouth dilated. Involucral leaves 2, deeply bilobed. Calyp- 

 tra pyriform, persistent, opening below the apex. Capsule oval, 

 4-parted to the base. Elaters attenuate at both ends, bispiral, 

 deciduous. Spores large, globose. Antheridia in the ventricose 

 bases of minute perigonial leaves. Leaves 2-lobed, the small 

 inflexed ventral producing rootlets. Amphigastria wanting. 

 Name from Lat. radula, a scraper or spatula, from the form of 

 the inner involucre. 



* Leaves rather closely imbricate or somewhat remote in No. 1. 

 f Stems dichotomously branching. 



1. R. tenax Lindb. Dioecious; stems brownish-green, 

 rigid, tenacious; leaves remote, scarcely decurrent, obliquely 

 elliptic-ovate, opaque, the cells rounded and strongly chloro- 

 phylliferous, the posterior lobe rotund-ovate, scarcely half the 

 breadth of the stem, the interior margin free, rotund, equal 

 to the width of the stem or more, the apex plane or scarcely 

 incurved; male spike borne on the side of the stem below the 



