328 Alexander W . Evans, 



No. 6947) British Guiana {Campbell, No. 6948), French Guiana 

 {Leprieur, No. 6977), Barbados (Herb. Hooker, No. 6952), and 

 Merida, Colombia [Moritz, Nos. 6949, 6950). These specimens are 

 among those mentioned in tlie Synopsis Hepaticarum, and all clearly 

 represent the same species. C. Wright's specimens of F. gibbosa from 

 Cuba, distributed in Hepaticae Cubenses; a large series from Jamaica, 

 collected by Harris, Underwood, Maxon, and the writer; and Spruce's 

 specimens from Tarapoto, Peru, distributed in Hepaticae Spruceanae, 

 have likewise been examined. All of this material is clearly F. gibbosa, 

 but the specimens from the Bahama Islands, recently reported upon 

 by the writer, ^ differ somewhat from the others and perhaps belong 

 elsewhere. 



With regard to the habitat of the species it occurs both on bark 

 and on rocks, frequently in exposed situations, and some of its pecul- 

 iarities seem to be associated with a xeroph^-tic environment. The 

 plants chng closely to the substratum and the stems branch frequently. 

 Sometimes the branches are variable in length and become irreg- 

 ularly subdivided ; sometimes they are more or less definitely Hmited 

 in growth and give the shoots a plumose appearance. Under the latter 

 circumstances the branches tend to be simple or else develop only one 

 or two short branches of a higher rank. In color the plants vary 

 from a greenish yellow to a deep dull brown and are often tinged with 

 whitish, owing to the fact that the margins of the leaf -lobes die and 

 bleach out through exposure. 



The leaves are very closely imbricated, especially in the variety 

 densissima, the imbrication affecting not only the lobes but the lob- 

 ules as well (Fig. 9, A). The lobes are convex when dry but are more 

 or less squarrose; when moist the apical portion spreads still more 

 widely from the axis, making the surface of the lobe somewhat con- 

 cave, but this appearance is never so pronounced as in F. squarrosa 

 (R. Bl. & N.) Dumort., a species which resembles F. gibbosa at first 

 sight and which grows in similar localities. The lobes in the present 

 species are broadly orbicular, measuring about 0.9 mm. in length and 

 1.2 mm. in width; they arch considerably beyond the axis and are 

 rounded at the apex. At the base a distinct auricle is developed and 

 this may be plane or more or less crispate (Fig. 9, D). This auricle 

 is usually so large and so strongly dilated that it covers over the 

 line of attachment of the lobe. The margin of the auricle is cren- 

 ulate from projecting cells, although the rest of the lobe is quite 

 entire. 



1 Bull. Torrey Club 38: 220. 1911. 



