160 FILTCES. 



base to the point ; segments of the pinnae varying much in the ex- 

 tent of their division and form, sometimes obovate, or inclining 

 to a square outline, and frequently in vigorous fronds pinnatifid, 

 with obovate sharply-toothed lobes ; the pinnules bear a flexuous 

 midvein which gives off alternate veins, the lowest anterior one 

 being distributed to the principal lobe, giving off venules to each 

 tooth ; the other veins, either branched or undivided, proceed to 

 the marginal teeth. Fructification generally sprinkling the whole 

 dorsal surface ; the sori are oblong, and are situated on the an- 

 terior side of the venules, occupying rather the middle of the 

 lobes than the centre of the pinnules ; they are covered by a 

 white, oblong indusium, which has a free, wavy margin ; the sori 

 are at first distinct from each other, but in process of ripening 

 they become confluent, and form irregular patches on the lobes. 

 Spore-cases bright brown. Crevices of rocks facing the sea, near 

 Hope's Nose. Rocky bank in a steep lane leading from Barton 

 into the Newton road. P. v.-viu. 



2. A. Adiantum-nigrum (blade Maidenhair Spleenwort.) 

 On hedgebanks, in crevices of rocks, and on old walls, very com- 

 mon. " Fronds ovate-triangular, twice or thrice pinnate, about 

 as long as the stipes, pinna3 and pinnules triangular, ultimate 

 subdivisions blunt, sharply toothed, clusters long, central" (Bab 

 Man. p. 426). (Sm. E. B. t. 1950. Moore, Nat. Print. Ferns, 

 t. 36. Moore, Handbook, p. 170. Sowerby, Ferns, t. 28.) Caudex 

 stout, short and tufted, bearing lanceolate, pointed scales, and 

 sending down numerous branching roots. The stipes, which is 

 of a shining dark purplish -brown colour, is usually as long as, 

 but sometimes longer than, the leafy portion of the frond. In 

 some specimens I picked this year, growing on hedgebanks among 

 long grass, the stipes were nearly double the length of the leafy 

 portion ; the dark colour of the stipes extends to the back of the 

 rachis. Length of the whole fronds from 3 or 4 to 18 or 20 

 inches, they present a rigid, leathery appearance, and are of a 

 dark shining green on the upper surface, but paler beneath ; their 

 form is deltoid or ovate-triangular, always tapering to a sharp- 

 pointed apex ; they are twice, thrice, and sometimes almost four 

 times pinnate. Pinnse obliquely triangular, thinning off at the 

 apex, the lowest pair nearly opposite, and generally, though not 

 always, longer than the rest ; the pinnae usually point upwards 

 towards the apex of the frond ; they differ very much in their 

 division ; the ultimate lobes are unequally toothed, the teeth being 

 more or less narrowed or obtuse, but always ending in a point. 

 The venation varies with the division of the frond ; the fructifi- 

 cation, however, is always situated near the giving off of the 

 branches from the midvein, and so occupies the centre of the 

 pinnules. Sori linear and crowded, covered with a whitish indu- 



