IIEBOULIA. 471 



mously branched, sinus often deep and narrow: prostrate, Hat, 

 costate, midrib broad and prominent, margin crenate, undulate ; 

 epidermis smooth ; below squamose, scales dark purple, imbricate, 

 quadrate-elongate ; radiculose, rootlets copious, slender, white, 

 proceeding from the midrib. Female receptacle pedunculate, 

 subrotund, afterwards hemispherical, deeply 4-5-lobed, proceeding 

 from the antical side of frond, at the base of the sinus ; surround- 

 ing the base of the female peduncle, also at the apex, there are 

 long, white, silky, hair-like processes, 1 and 2 cells wide. 

 Perianth wanting. Calyptra minute, lacerate, persistent at the 

 base of the capsule. Capsule composed of several layers, the 

 innermost without any spiral threads, globose, rupturing irregu- 

 larly, teeth not revolute. Spores muriculate, pale yellow with 

 hyaline border when young, brown when old and dr3\ Elaters 

 very closely twisted, narrow. Antheridia narrow, numerous, 

 immersed in the antical, sessile, crescent-shaped discs. 



Fruits in Spring and early Summer. 



Dimensions. — Fronds 1 to 2 inches long, 5* to (>• mm. broad; 

 female peduncle 1 to 2 inches long; spores •! mm. diam. ; elaters 

 '35 mm. long. 



Hab. — On dryish, exposed cracks oi" rock filled with earth. 

 Somewhat rare. 



1. Extremely rare, Paul Hill, Cornwall, //'. 6V/'yv/o/r. 2. Hamp- 

 shire. 3. Sydenham, j\Iarf//ji ; lane leading from liustliall Com- 

 mon to the High Rocks ; Lamberhurst Quarter, J e inter ; Boro' 

 Green; Ightham ; Halstead, Kent, E. j]f. Jlolii/c-s. 4,5. Weaver 

 Hill, Staffordshire, 7^. Gdnirr. 7. On rocks, Barmouth, Merionetli- 

 shire, Rer. T. Sal toe//. Dr. Cdrrhujiou tS" // . H. P. 8. Castleton, 

 Derbysliire, /. Uliiteliead. \). Dalton Crag, Lane, ./. A. Wheldan. 

 10. Ingleboro, iJr. Carr'nujtoii ; Dentdale, G. S fabler; Thornton 

 Force, ir. West ; Settle, 7/. F. Parsons ; Malham Moor, V. l/'e.s/ ■ 

 Ingleton, Jf. II. P. 11, 12. Among limestone rocks, Levens 

 Park, Westmorland, G. Slahler. 13. Back of Kenmure Castle, 

 New Galloway ; rocks near Grennan, Dairy; about Kirkcudbright, 

 /. McAiidreir. 15, IG. Ptather common on exposed rocky banks, 

 Moidart, West Inverness, S. J/. j\faevicar. 



