174 



ASPLENIUM ADIANTUM-NIGRUM. 



fronds subquadripinnate. The lowest pinna?, which are the 

 largest, are opposite, and of a similar outline to the frond 

 itself. The apices of the frond and pinnules caudate, with a 

 few sharp, deep, and distant teeth. The lower lobes are 

 three-toothed, those above bifid, whilst at the apex only simple 

 toothed. Veins furcate, slender, but very distinct. Sori very 

 narrow, linear, and situated near the centre of the pinnules. 

 It differs from the normal species in being more subdivided, 

 in its thinner and more papery texture, and in the presence 

 throughout of linear-acute erect segments and teeth. For 

 fronds I am indebted to Mr. G. H. Allcock, and to Mr. Joseph 

 Sidebothara. 



Fig. 515.— Middle pinna;. 



MiCRODON, Moore. (Fig. 515.) — A distinct variety, found in 

 Guernsey and near Barnstaple by the late Mr. C. Jackson, 

 and in Devonshire by the Rev. J. M. Chanter. Fronds six 

 to eight inches in length, broadest at the base, where nearly 

 three inches across, pyramidal, with an irregular outline, owing 

 to the unequal length of the pinnae. Pinnee distinctly pinnate 

 at the base, but slightly adnate and decurrent above, and in 

 the upper part are confluent into a broad irregular pinnatifid 

 apex. The outline of the distinct pinnre hastate, owing to a 

 rounded auricle, both on the anterior and posterior sides. In 

 the basal pinna3 the auricles become lobes divided half-way 

 down to the costa, above the auricle they taper to an acute 

 point. The margin is everywhere minutely and sharply 

 denticulate. Sori numerous, placed near the costa, mostly 

 scolopendrioid. 



