FILICES. 41 



following summer, except in exposed localities ; they are erect, or 

 pendent when luxuriant. 



Yar. /3 is usually a larger plant, the fronds 6 to 20 inches long, 3 to 

 5 inches broad. 



Var. y has the fronds 4 inches to 1 foot long, by 3 to 7 inches 

 broad. It is to this variety that the handsomest forms, so much coveted 

 by fern-growers, belong. Most of these, however, are abnormal 

 developments, which is shown by the frond being either wholly 

 or partially barren, and by the irregularity of the divisions of the 

 primary segments. The most regular of all the forms, which is also 

 occasionally fertile, is that from Goderich Castle, Herefordshire, 

 which is named " omnilacerum " by Mr. Moore. The true Cam- 

 bricum is always barren. The form called crenatum by Mr. Wol- 

 laston, which I have from Mucrus, Killarney, appears to be really 

 the Cambricum without monstrous development. This comes very 

 near var. /?. serratum, but has the frond much broader in proportion. 

 Mr. Moore gives Saltoun Castle, Kent (S. Grey) ; Devonshire (Rev. 

 J. M. Chanter) ; Conway (Dr. Alchin) ; Ruthin, Denbigh (E. Pritchard) ; 

 the Craigs, near Dumfries (W. G. Johnson) ; Mucrus, Killarney (Dr. 

 Alchin) ; as stations for the form crenatum. (Moore, ' Nat. Print. 

 Ferns,' 8vo. ed., vol. i. p. 67.) 



Common Polypody. 



Tribe II.— GRAMMITIDE.E. 



Caudex not growing in advance of the fronds, the stipes of which 

 is not articulated to the caudex, and does not separate from it. Sori 

 elongated or linear, or more rarely nearly round, attached to the back 

 of the veins, without an indusium. 



GENUS F.-GYMNO GRAMME. JDesv. 



Fronds produced from the apex of the caudex, usually approxi- 

 mated or tufted ; stipes not articulated to the caudex. "Veins forked, 

 free. Sori linear or oblong, rarely roundish, on the back of the ulti- 

 mate veins, and often occupying their whole length, frequently 

 ultimately confluent, not covered by the reflexed margins of the frond. 

 Indusium absent. 



Name from yv//.vo's (gumnos) naked, ypa/xfi-)] (gramme) a line, referring to the naked 

 lines often formed by the sori which are not covered by an indusium. 



VOL. XIT. 



