178 



The Na-turalist. 



Ings, and Askham Bogs — the latter being perhaps the best of all. 

 During the latter part of the year 1877 I occupied myself with a 

 thorough exploration of the fern-flora of the city walls. Commencing 

 at Lendal Bridge I went completely round the city, except for that 

 part lying between Lord Mayor's Walk and Bootham Bar, which is 

 not open to the public. 



Altogether, I am able to enumerate the very fair total of thirty-four 

 species, growing within the district. Of these, one — Nephrodium cris- 

 tatum, is new to Yorkshire, if not to the North of England, and three 

 — As]jle7imm Ti'icliomanes^ A. Adiantum-nigrmny and Scol(ypendriiim 

 vulgare — are, I believe, new to the neighbourhood of York. 



Pteris aquilina. — Less common than in some parts of England, but 

 certainly far from rare. It is cut down by the earliest frosts of winter 

 — often by the beginning of September. Among its localities are 

 Strensall, Askham, Hobmoor, Acomb, Naburn, Stockton, York, &c. 

 At Strensall it has been measured lift. 6in. high. In September, 

 1877, I was searching that part of the city walls situated just over 

 the Old Station, when I came upon two diminutive ferns which I was 

 totally unable to distinguish, but Mr. Backhouse afterwards informed 

 me that they belonged to the present species. The shape of the 

 fronds was somewhat triangular, the longest did not exceed 1^ inches 

 in length, and they grew in tufts unlike bracken, when growing in the 

 ground. I afterwards found in several other spots on the walls on the 

 west and south-west sides of the city, about half-a-dozen other plants 

 showing more clearly the species, the fronds being adult, though none 

 exceeded three inches. A bifid variety occurs at Linton-upon-Ouse 

 and elsewhere. 



Lomaria spicant. — South of the city I have not met with this, but on 

 the north it often grows fine and abundant, as at Langwith Woods, 

 Strensall, and, in smaller quantities, at Stockton, Castle Howard, and 

 Dunnington. The fertile fronds stand erect, often reaching the height 

 of 2ft., but the barren ones seldom reach that height, are procumbent, 

 and often remain green throughout the v»dnter. Both Mr. Backhouse 

 and myseK have on rare occasions met with fronds of this fern near 

 York which appeared to be intermediate between the barren and fertile, 

 the latter being most apparent in tLe lower pinnae while the upper 

 ones bore some fructification. Both sorts of frond are not uncommonly 

 bifid or trifid. I got eight such fronds off one plant at Castle 

 Howard, and a quantity from the roadside near Wiggington. A barren 

 variety with the fronds three inches broad, the pinnce also broad and 

 curved upwards, with their lower edges somewhat deeply serrated. 



