40 HEPATIC^'. 



geniculate at the joints. Capsule globose hyaline or pale brown- 

 membranous, dividing to about two-thirds into 4 valves, composed 

 of two layers, inner spongy. Elaters persistent at the apex of 

 the valves, usually unispiral. 



1. Lejeunea Mackaii (Hook.), S^neng. 



Jimgermania Mackaii, Hook. Brit. Jung. t. 53 (1816). 

 Phragmicoma Mackaii, Dum. Comm. Bot. (1822). 

 Lejeunea Mackaii, Spreng. Syst. Veg. 4, p. 233 (1825-7). 



Monoicous, densely but shallowly csespitose, small, reddish- 

 brown to blackish olive-green. Stems creeping, imbricate, firm, 

 more or less dichotomous, sometimes with only one innovation 

 proceeding from below the $ flower; cortical cells larger than 

 the inner, walls brown, 30-35, inner with pellucid walls 10 x 12. 

 Leaves imbricate, often densely, distichous, horizontal or patent- 

 divergent, unequally bilobed, antical lobe slightly convex, sub- 

 semicordate, ovato-rotund, all very obtuse, postical lobe 3 to 4 

 times smaller than the antical, subquadrate or ovate, free 

 margin involute, bidentate, ventricose; cells smallish, 4-, 5- and 

 6-angled, walls thick, angles slightly thickened. Stipules twice 

 shorter than leaves, much wider than the stem, rotundo-cuneate, 

 entire or retuse, never cordate or decurrent. Bracts unequally 

 bilobed, antical lobe ovato-obtuse, margin entire, postical from 

 half to one-third the size, oblong-obovate, margin entire. Bracteole 

 oval, apex retuse. Perianth projecting about half beyond the 

 bracts, obcordato-obovate, gibbous below, compressed, slightly 

 convex, mouth contracted, dentate, composed of a single layer ot 

 cells, about 150 round the middle. Capsule spherical, delicate, 

 whitish, dividing down to the base into 4 valves. Elaters 

 bi spiral. 



Androecia on long lateral branches not produced from the axil 

 of the leaves ; perigonial bracts closely imbricate, smaller than 

 the stem leaves, subequally bilobed, antical lobe oblong, postical 

 similar but slightly smaller, turgid ; antheridia two, large, 

 globose. 



Dimensions. — Stems J to 1 inch long, with leaves 1*5 mm. to 



