9 6 BRITISH FERNS. — SUB-ORDER II. TRIBE 9 . 
widely and squarely dentate than “ stenomenon ” ; upper half of 
frond widest ; marginal line close to rachis at the base, yet be- 
coming close to the margin at the apex. 
37. turgido-irregulare, Moore. Found at Whitby and Nettle- 
combe. More irregular and more profoundly lobed than “ turgi- 
dum and marginate. 
*38. undosum, Lowe (named in error “ marginato-undulatum,” 
Lowe). Raised by myself, ibxij inches. Shining green. A 
marginate undulatum, with the undulations unusually close. 
39. undulato-contractum, Lowe. Found in Devon by the late 
Mr. C. Jackson. Undulate and irregular in outline ; contracted 
in part of the frond. Partially marginate. 
40. undulatum, Lowe (marginato-undulatum, Barnes). Found 
in 1865, at Heversham Head, by Mr. J. M. Barnes. Also in 
County Clare, by Mr. O’Kelly. A dense, undulate form. 
41. venosum, Lowe (marginato venosum, Barnes). Found in 
1874, at Flookborough, by Mr. J. Stewardson. Known by its 
prominent veins. 
Group IV. Margin jagged. 
Section a. CRENATUM. (Margin altered.) 
1. aduncum, Moore. 10X1 inches. Conspicuously lobate ; irre- 
gular, and apex bifurcate. 
2. Aireyi, Lowe (fissum Airey, Barnes). Found in 1877, at Miln- 
thorpe, by Mr. T. Airey. A neat, narrow form. 
3. alto-lobatum, Lowe. Found at Carron, Co. Clare, by Mr. 
O’Kelly. Deeply lobed and truncate. 8x ij inches. 
4. angustato-nitidum, Lowe. Found at Lower Commons, Co. 
Clare, by Mr. O’Kelly. i2Xof inches. Densely fimbriate; having 
a shiny frond. 
5. contractum, Wollaston. Found in Clare, Guernsej', Smeerset, 
Nettlecombe, and Ruthin. 10 X 1 inches (in widest part). Crenate ; 
contracted below the densely flabellate multifid crest ; partly 
supra-soriferous. 
6. crispo-fissum, Barnes. Found in 1877 at Milnthorpe by Mr. T. 
Airey. A beautiful, small, narrow, crispy variety. 
7. dareoides, Wollaston. Raised by the late Mr. Ehvorthy. 
Length, 12 inches. Depauperate, and almost pinnatifid ; with lax 
teeth. The apex much the broadest part of the frond. 
8. dentatum, Clapham. Length, 8 inches. Margin irregular and 
conspicuously dentate. Apex almost normal. 
9. erosum, Lowe. 8x1 inches. Outline irregular and here and 
there erose ; interruptedly marginate and dentate. A good form 
has been found at Mucknish, Co. Clare, by Mr. O’Kelly. 
10. fissidens, Wollaston. Found in N. Devon. Deeply cut and 
narrower than “ fissum.” 
11. fissile, Moore. Found at Nettlecombe by the late Mr. El- 
worthy, and at Malton by the late Mr. C. Monkman. 12x1 
inches. Irregular, and sub- pinnatifid ; and crenate-dentate. 
