POLYSTICHUM LOXCHITIS. 71 



The fronds, wliicTi are linear-lanceolate in shape, are pinnate, 

 the pinnae being numerous and crowded, briefly stalked or 

 sessile, and lanceolate-falcate, acute, on the anterior base 

 auricled, the posterior base being obliquely cuneate, the 

 margins covered with spiny serratures. 



The stipes mostly very short, varying from half an inch to 

 three inches in length, and covered with a profusion of large, 

 brown-coloured, chaffy scales, the rachis having numerous 

 narrower scales. The caudex thick, scaly above; roots wiry 

 and dark-coloured. 



The length of frond is usually from six to eighteen inches, 

 occa<ionallv as much as twenty-four inches. Colour deep green 

 above, paler beneath. 



Veins consisting of a midvein, which extends to the apex of 

 the frond, from which proceeds a vein up each pinna, which 

 is forked and branching two, three, or four times, extending 

 veinlets into each of the marginal teeth. 



The fructification is mostly confined to the upper half of the 

 frond; the sori being situated in a line on either side of the 

 midvein, about midway between the midvein and the margin; 

 circular. Indusium membranaceous, orbicidar, and attached to 

 the receptacles by a brief central stalk. Spore-cases globose 

 and numerous; spores roundish and small. 



Although there are only two varieties of this species described, 

 still the Irish form is so distinct that it seems desirable to 

 distinguish it fr-om the English form, which I propose to do 

 under the name of Confertum. 



CoxFERTUM, Lowe. (Fig. 48.) — The Irish form of Polystichum 

 lonchitis, smaller in size, the pinna; more numerous, narrower, 

 and more crowded together, overlapping each other. Pinnae 

 usually opposite or siib-opposite below, and alternate above. 

 In this form the auricle of the base is hid by the pinna 

 immediately above overlapping it. 



Mr. AVollaston has described two other varieties, namely: — 



Multijidum. — Havmg the apex divided. 



Proliferum. — Producing small bulbils in the axils of the 

 lowermost pinnae. 



The variety Multijidum is not constant, and the variety 

 Proliferum is of the normal form, it is therefore unuecessarv 

 to s^ivc illustrations of them. 



