WILLIAMS: CALYMPERACEAE OF NORTH AMERICA 395 
rounded to the scarcely acute apex and with very distinct teniolae 
of three or four thicknesses of cells and five or six cells wide ex- 
tending from some little distance above the base to about an equal 
distance below the apex, with three to six rows of cells between 
the tenola and margin; costa. about 100 » wide a little above the 
base, nearly percurrent, in cross-section, showing five or six guide- 
cells, large stereid bands above and below them and outer cells 
somewhat differentiated; cells of blade in upper leaf mostly 
roundish or slightly elongate, mamillose on the ventral, flat on 
the dorsal side, the median cells 6-7 wu in diameter, gradually 
changing toward the base to the not very numerous rectangular 
cells which are more or less colored and never form distinct can- 
cellinae. [Fic. 12.] 
Tyre collected in the vicinity of Utuado, Porto Rico, on wet 
rocks, March, 1915, E. G. Britton 5206 (herbarium of the New York 
Botanical Garden). 
DISTRIBUTION: known only from type locality. and La Juanita, 
near Las Marias, Porto Rico. 
NEw. YorK BoTANICAL GARDEN. 
