384 



author in 1835 \^\\\\ Jnngermania byssacea Roth, as a type species. 

 It was not accepted by the authors of the Synopsis Hepaticarum 

 1844-7, but the same is true of many other early genera not pro- 

 posed by Nees, one of the authors of the work. It was after- 

 wards accepted by Gottsche, and later hepaticologists have ac- 

 cepted it without question, Schiffner alone excepted, as above 

 stated. Of its sub-genera, as noted below, Nowellia differs most 

 widely in its general facies from the rest of the genus, but none of 

 the groups seem sufficiently separate for generic distinction. The 

 genus as here recognized can be characterized as follows : 



Cephalozia Dumort. 



Gametophyte mostly small or minute, usually close-creeping; 

 stems branching ventrally or rarely laterally, often flagelliferous ; 

 leaves obliquely placed, succubous, bifid from one-third to over 

 one-half their length ; leaf cells usually large, transparent, mostly 

 hexagonal; under-leaves usually wanting on the stems, often 

 present on perianth-bearing branches. Perianth long, triangular, 

 with a narrowed, toothed or ciliate mouth. 



Sporophyte an oval or oblong-cylindric capsule on an ephem- 

 eral seta, varying in different species from 2 mm. to 2 cm. long. 



The genus includes some sixty species well distributed, but 

 best known from the North Temperate zone. Fourteen species 

 are found in America north of Mexico. These can be distin- 

 guished by the following table, which has been constructed with 

 special reference to material in which the perianth characters can 

 not be seen : 



Leaves deeply concave or somewhat saccate with two long, curved, slender divisions ; 

 perianth on a short ventral branch. § NowELLiA. 



Leaf cells 20-25 l'-> isodiametric I. C. ctirvifolia. 



Leaves not deeply concave nor saccate. 



Branching ventral ; leaves bifid, but the leaf margins otherwise entire. 



Leaves wider than the stem ; involucral leaves not united. § Eucephalozia. 

 Leaves small, 0.35 mm. or less long. 



Leaves wide (0.35-0.4 mm.) decurrent at base; leaf-cells 35-40^; 

 dioicous; perianth fleshy (3 cells thick at base.) 



2. C. media. 

 Leaves narrow (0.2-0.25 mm.) not decurrent at base; leaf-cells 

 20-30 // ; perianth thin. 



Leaves strongly narrowed above the base ; perianth obovate- 

 oblong. 3. C. Sullivantiae. 



