4296 350 
below the terminal one, 12—-15 cm. long by 31/2 cm. broad at the middle, 
pale yellowish-green beneath, the margins dentate throughout, the abruptly 
acuminate apex serrulate, unequally cuneate at base, the upper (inner) 
side nearly parallel to rachis, the lower cuneate; some minute scales on 
the flattened midrib beneath. Veins simple ‘or more often once or twice 
furcate; short recurrent veins present. Sori well within the margin with 
13—16 sporangia. By its long-stalked pimnee with few but proportionally 
very broad pinne of a yellowish-green culour it seems to deserve a name 
of its own; I propose to name it A. siamensis n. sp. 
