4 Pearson, Hepatics from the Cameroons 



Observations. — As I have only met with two stems of this 

 minute species I hesitate to name it, although Stephani (3) in 

 his " Sp. Hep." does not record any Drepanolejeunea from 

 Africa with margin of leaves minutely denticulate. 



Ceratolejeunea Saxbyi, n.sp. Pearson. 



Monoicous. Medium size ; reddish-brown in colour ; 

 loosely caespitose or creeping amongst other mosses or 

 hepatics. Stems irregularly pinnate, alternate, 2 to 3 cells 

 wide, innovant branch arising from base of perianth, some- 

 times long and again innovant, rarelv two innovant branches. 

 Leaves horizontal or slightly ascending, imbricate, slightly 

 concave, semi-rotund or oblong, apex acute or more rarely 

 obtuse, margin entire, upper margin rounded, ampliate, cross- 

 ing the stem, lower margin nearly straight or slightly curved, 

 branch leaves sometimes ovate-acute, distantly denticulate ; 

 cells quadrate or oblong-quadrate, middle and basal cells 

 medium size, marginal cells very minute, a remarkable grada- 

 tion in size from the middle to the margin, no trigones ; 

 ocellate, 1-2, or sometimes more, ocelli oblong, near the base ; 

 lobule very small, about 5 times smaller than the lobe, oval 

 or oblong, free margin unidentate, tumid, keel rounded, 

 smooth, lobule sometimes reduced to a mere line or wanting. 

 Underleaves 3 to 4 times broader than the stem, approximate, 

 broadly ovate, bifid to one-third, segments acute, sinus acute, 

 rarely rounded. Bracts rotund, apex acute, sparingly denti- 

 culate, lobule 2 to 3 times smaller, oval, sparingly denticulate 

 or entire. Bracteole oblong-oval, bifid to one-third, segments 

 acute, sinus acute. Perianth ovate, upper portion 5-keeled, 

 keels smooth, mouth with 4 horns. Amentula sessile, short, 

 2 to 3 pairs of bracts ; bracts, lobe rotund, apex obtuse, lobule 

 slightly smaller, oval, apex obtuse. Water sacs (utricles) 

 more or less present on the stems. 



Dimensions. — Stem \ to 1 inch long ; .075 mm. diam. ; with 

 leaves 1.25 mm. wide; leaves .7 mm. by .45 mm., .65 mm. by 

 45mm., .6mm. by 4mm., lobule .15mm. by .1 mm.; cells, 

 middle .03 mm., .04 mm. by .03 mm., ocelli .05 mm. by 

 .03 mm., marginal .01 mm. ; underleaves .4 mm. by .4 mm., 

 .35 mm. by .35 mm., .35 mm. by .3 mm., segments .075 mm. ; 

 bracts, lobe .7 mm. by .5 mm., lobule .4 mm. by .2 mm.; 

 bracteole .5 mm. by .375 mm.; perianth .6 mm. by .4 mm.; 

 male bracts, lobe .2 mm. by .15 mm., lobule .15 mm. by .1 mm. 



