McArdle — On the Eepaticce of the Hill of Howth. 119 



crenulata is not mentioned in Dr. Moore's work, I have exa- 

 mined specimens collected by him on Howth, and find amongst 

 them a fine form, with the margins of the leaves beautifully 

 ciliated. They were also seen by the late Professor Lindberg, 

 to whom I sent a small portion, with two others from Dr. 

 Moore's Herbarium, which he collected in the Counties Kerry 

 and Mayo, and which I made out to be distinct from the type. 

 These Lindberg named C. coralloides and C. ohhisa, which, with 

 other rarities, were included in a paper read by me, and 

 published in the Proc. Ptoy. Dub. Society, vol. iii., 1880. I 

 have not gathered C. crenulata on Howth Hill.] 



31. Fellia epiphylla (Dill.), L. Hook. Brit. Jung. tab. 47, figs. 1, 4, 

 8, 17 ; Eng. Bot. t. 771. Plentiful in moist places on the 

 hill ; abundant on the sides of drains in Ballykill plantation. 



32- '^'Pellia ealycina (JSTees), Taylor. Jung. e])ip'hijlla,\2.Y. y furcigera ; 

 Hook, Brit. Jung. t. 47, figs. 18, et 2, 3, 9, 10-12; Eng. Bot., 

 SuppL, t. 2875. Rare ; on a small, shallow bog by the mar- 

 gins of a brook near Ballykill. 



33. Metzgeria furcata (Linn.), Dumort. Hook. Brit. Jung. t. 55 et 



56. On the trunks of trees and on clamp rocks plentiful. 



34. "^'Metzgeria conjugata (Dill.). Lindberg's Monographia Metzgeria, 



p. 29, fig. 6; Dill. Hist. Muse, t. 74. Autoecious, stems 

 robust, not much elongated, more or less dichotomous ; irre- 

 gularly pinnated or decomposite linear, but narrower in some 

 parts of the frond than in others, often narrowed suddenly to 

 the middle, in transverse section semi-lunar ; margins remote, 

 hairs longish, singly or often in pairs on the margin, and 

 divergent. Very rare in this station, growing on Frullania 

 tamaresci ; amongst the rocks near the Baily Lighthoiise. 



35. Ftccardta mtdtifida (Dill. Linn..), Gv. Eng. Bot. t. 186. Plentiful 



on wet, boggy places on most parts of the hill. 



36. Riccardia pinguis (Linn.), Gr. Hook. Brit. Jung., t. 46. Plentiful 



on a small bog near the quarries opposite Sutton ; abundant 

 on a bog near Ballykill. 



