446 A. W. JEvans — Hawaiian Ilepaticoi of the Tribe Jubuloideoe. 



A very close ally, apparently, of M. albicans is M. crassitexta, 

 described by Jack and Stephani from sterile specimens collected on 

 the Fiji Islands. This species differs, however, in its more deeply 

 cleft underleaves. The true 3£. cucidlata^ has ovate, long-decurrent 

 underleaves and differently shaped leaves. 



15. COLOLEJEUNEA (Spnice) SchiflEn. 



Lejeunea subgenus Colo-Lejeunea Spruce, Hep. Amaz. et And. 291. 



1884. 

 Cololejeiinea Schiffn.; Engler & Prantl, Nat. Pflanzenfam. i', 121: 



1893. 



Plants variable in habit, very small to medium-sized, pale green 

 varying to brownish-green: leaves attached by a very narrow base, 

 the lobe widely spreading, rounded to subacute at the apex, entire, 

 crenulate, or denticulate, lobule inflated or plane, very variable in 

 shape; stylus present, sometimes reduced to a single cell : under- 

 leaves absent, in their place clusters of rhizoids, one for each leaf : 

 leaf-cells mostly thin-walled, often papillose : ? inflorescence terminal 

 on a principal branch or on a short branch, innovating on one side, 

 the innovation often floriferous ; bracts similar to the leaves ; peri- 

 anth very variable: (^inflorescence occupying a short branch or 

 terminal, sometimes on the main axis. 



According to our present knowledge, Cololejeiinea is represented 

 by more Hawaiian species than any other genus of the Lejeuneeae, 

 and it is probable that many interesting forms still remain undiscov- 

 ered. The majority of the species ai*e small and some of them are 

 very small, and this fact, together with the epiphyllous habit of most 

 of the tropical species, sometimes makes the plants difficult of detec- 

 tion. Of tjie seven Hawaiian species, six belong in Dr. Spruce's 

 section Leptocolea^ which is exclusively tropical, while the seventh 

 species, C. CooJcei, represents his section Physocolea, which is found 

 in both tropical and temperate regions. These two sections are 

 almost of generic importance. Most of the Hawaiian species show 

 the disc-shaped gemmre, whose structure and development has been 

 fully described by Goebel.* 



* Ann. du Jarcl. Bot. de Buitenzorg, vii, 49ff. 1888. 



