AND HEPATICOLOGY OF NORTH AMERICA. (65) 11 



Diagnosis secundum specimina Schweinitziana in Herb. Acad, 

 Nat. Sci. Philad. 



HAB. In Carolina Superiors prope Salem. 



2. N. VALVATA, Sulliv. '. fronde diametro tri-octolineari ; involucro 



horizontal] deflexo corniformi ; capsula elongato-cylindrica cur- 

 vula sutura colorata semper instructa ; sporis luteolis subfus- 

 cisve. 



HAB. In humidiusculis circa Columbus Ohionis, sat frequens. 

 Maturescit ^Estate-Autumno. 



3. N. MELANOSPORA, Sulliv.: capsula sutura omnino nulla; colu- 



mella appendiculata ; sporis atrofuscis dimidio majoribus quam 

 in praecedente : csetera conveniunt. 



HAB. In iisdem locis cum priore ; rarissima. 



We have here a genus that cannot be placed in any of the tribes 

 of Hepaticae as now circumscribed. Its station is between Antho- 

 cerotese and Riccieae. The frond is undistinguishable from that of 

 Anthoceros, to which genus it also approaches in its tendency to 

 bivalve dehiscence, in the presence of a columella, and in the manner 

 of ripening the spores, which commences at the apex of the capsule 

 and proceeds towards its base, so as to present spores in all stages 

 of development. A relationship to Riccia is shown by the inclosure 

 of the subsessile capsule in the frond, or rather in a protruded por- 



* 



tion of it, as also by its embedded anthers, and the absence of any 

 thing like elaters. Unlike both of the above genera, the calyptra, 

 if present at all, vanishes at an extremely early stage of the plant's 

 growth ; for, in many dissections of N. valvata and N. melanospora, 

 at all periods of growth, I have never seen a calyptra. The only 



