HANDBOOK OF BRITISH HEPATIC/E. 233 



exserted. Calyptra surrounded by numerous abor- 

 tive pistillidia. Capsule round, dark brown, on a 

 long white pedicel. Spores yellow-brown, c^ranu- 

 lose. Antheridia axillary, olive-green, shortly 

 pedicellate. 



Genus 31. ACROBOLBUS, Nees. 



Involucre scale-like, of one leaf. Perianth 

 terminal, affixed laterally at the margin ; stem 

 descending below the apex, without radicles ; 

 capsule four-valved. Elaters double, amongst 

 the spores, deciduous. — Gott. L. and N. S^m. 

 Hep. p. 5. Gymnanthe, Tayl. Dnmori. Hep. 

 Eur. /. 3,/ 35- 



Plants without stipules, leaves subcurrent, entire. 



Involucre terminal, obovate, seated at right 

 angles with the stem, bulbous and rooting on the 

 ventral aspect. Perianth absent. Calyptra attached 

 to the bulbous base of the receptacle, surrounded 

 by, and concrete with, the entire portion of the 

 involucre, and bearing around the apex the abor- 

 tive pistillidia. Antheridia terminal on separate 

 shoots. Plant small, creeping, semi- parasitic. 

 Leaves succubous, ascending, two-lobed. Amphi- 

 gastria absent from stems. — Carr. Hep. p. ^i. 



Spruce holds that Aerobolbiis is the direct con- 

 tinuation of species of Nardia {^Uieidaria), whose 

 gibbous rooting involucre is the precursor of the 

 pendulous bulbiform pouch of Aciobolhus Wilsoni, 



