s 
Vol. 38 No. 5 
BULLETIN 
OF THE 
TORREY BOTANICAL CLUB 
JUNE, to11 
Hepaticae of Puerto Rico 
X. COLOLEJEUNEA, LEPTOCOLEA, AND APHANOLEJEUNEA 
ALEXANDER WILLIAM EVANS 
(WITH PLATES II AND 12) 
COLOLEJEUNEA 
Although the vast majority of the Lejeuneae develop con- 
-spicuous underleaves, there are two recognized genera, Metzgeriop- 
sis and Cololejeunea, in which underleaves are completely lacking. 
In fact Leitgeb* has shown that in Cololejeunea calcarea (Lib.) 
Schiffn. the postical segments cut off from the apical cell give rise 
to no appendages except rhizoids and that the hyaline papillae. 
which usually grow out from these segments, even in the absence 
of underleaves, are here developed from the lateral segments 
instead. In all probability the conditions which he describes for 
C. calcarea exist in allied species. The lack of postical appendages 
is also characteristic of Radula, although the relationship between 
this genus and the Lejeuneae is somewhat remote. 
The genus Meizgeriopsis contains a single species, the East 
Indian M. pusilla Goebel, and is especially noteworthy for the 
fact that leaves are borne on the sexual branches only. The 
vegetative portion of the plant consists of a flat dorsiventral thallus 
but one cell thick, bearing marginal multicellular hairs and branch- 
ing in a pinnate manner. The genus Cololejeunea, as at present 
defined, contains about seventy-five species and bears leaves on 
* Unters. iiber Lebermoose 2: 7. 1875. 
[The BULLETIN for May 1911 (38: 205-250. pl. 9, 10) was issued 15 Je 1911.] 
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