386 
THE FERN WORLD 
and the spore cases. When for purposes of examination this 
scaly covering has been removed, the venation is found to 
consist of a somewhat wavy mid-vein, with alternately 
branched and forked venules, proceeding to the margin and 
hearing upon them elongated, hut otherwise somewhat 
irregularly shaped masses, of spore cases. The indusium in 
Ceterach is very imperfect, consisting only of a sort of ridge, 
running in a line with the clusters of spore cases, hut not 
covering them. Indeed the presence of a perfect indusium 
is not necessary on account of the protection afforded by the 
dense covering of scales. The upper surface of the frond is 
dark green, the rachis being sometimes of a paler green, and 
very clearly defined as it takes a wavy course between the 
pinnae ranged on each side of it. The scales on the under 
surface of the frond, being projected slightly beyond the leafy 
margins of the pinnae, afford a beautiful contrast with the 
deep green upper surface. There are seven or eight recorded 
variations from the normal form of this Fern. 
Distribution. — On the continent of Europe Asplenivm 
ceterach occurs in Austria, Belgium, Croatia, Dalmatia, 
France, Germany, Greece, Holland, Hungary, Italy, 
Portugal, the South of Russia, Spain, Switzerland, Tran- 
sylvania, and Turkey. In Asia it is found in Armenia, Asia 
Minor, the Caucasus, Erzeroum, India, Siberia, and the Ural 
Mountains. It is also an inhabitant of Bengal. In Africa 
it occurs in Algiers, and in the Azores, the Canaries, the 
Cape de Yerd Islands, and Madeira. In England it is 
found in the following counties : — Chester, Cornwall, Cumber- 
land, Derby, Devon, Dorset, Essex, Gloucester, Hants 
(including the Isle of Wight), Hereford, Kent, Lancaster, 
Monmouth, Norfolk, Northampton, Northumberland, Notting- 
ham, Oxford, Salop, Somerset, Stafford, Surrey, Sussex. 
Warwick, Westmoreland, Wilts, Worcester, and York. In 
Wales it inhabits the counties of Anglosea, Brecknock 
