472 HEFATIG^. 



I. DunkeiTon, Br. Taylor ; Dingle Bay, i^y. Carrington ; lime- 

 stone rocks near Cork and Fermoy, /. Carroll ; abundant on the 

 walls of the bridge at Cong, Co. Galway ; Sillaghbraes, near 

 Larne, Co. Antrim, Dr. D. Moore ; on sandy ground at the 

 North Bull, near Dublin, D. Mc Anile ; Island of Eathlin, Co. 

 Antrim, >S'. A. Steicart. 



Found on the Continent, Asia, North and South America, 

 Java, Japan, Australia, New Zealand. 



Obs. — Much rarer than Preissia conim/dafa, with which it is 

 frequently confounded. "Easily distinguished by the deeply 

 divided 4 -5- fid receptacle, which is barbate beneath and at the 

 base of the peduncle, and by the sessile antheridia, whereas the 

 receptacle of Preissia cohtmutata is marked on the top with a 

 cruciate crest and the ^ pedunculate. "^ — Dr. Carrington. 



Another character at once makes the difference certain — viz., 

 the innermost layer of the walls of the capsule of P. cornmutata 

 have in their cells reddish-brov/n spiral threads, whereas they are 

 absent in this species. 



Description of Plate CCX. — Figs. 1-4. Fertile plants natural 

 size. 5. Frond, postical view. 6. Plant with young (r/ c? ) and 

 {h ?). 7. Cross-section of pedicel X 11 (W.H. P.). 8-13. Female 

 receptacles. 14. Ditto, showing young capsule. 15,16,17. Cap- 

 sule in different stages x ?. 18. Spores x ?. 19. Spore and 

 elater, more highly magnified. 20. Cross-section of male recep- 

 tacle x ? (Bischolf ). 



Genus 48. PREISSIA, Conla. 



Preissia, Corda in Opiz Naturalientausch (182D) ; Nees, Eur. Leberm. (1838). 



Frond obcordate, sparsely furcate, margin thin, increasing by 

 joints from the apex, pores conspicuous, bearing the peduncle 

 from a sinus of the terminal lobe. Gemma.^ wanting. Female 

 receptacle pedunculate, hemispherical, 4-6-lobed, rays of the 

 lobes shorter, rib-like, only free at the inferior part, librous-barbu- 

 late underneatli. Perianth obconically campanulate, angular, 



