MARCHANTIA. 467 



of the thallus, covered by the scales ; texture between flesljy and 

 membranaceous ; on the antical surface there are numerous 

 stomafca, each situated in tiie centre of a diamond-sliaped area, 

 the postical side beuig furnislied witli numerous brownish scales. 

 Female receptacle produced from the g-rowing- points of the 

 thallus, pedunculate, hemispherical, deeply divided to the base 

 into G to 12, usually 9, linear decurved rays, coverinj^ as many 

 involucres, wliich are united at the base and mixed with minute 

 chafty scales. Peduncle 2-channelled. Involucre oblong-, open 

 at the end and torn, enclosing an ovate quadrifid perianth. 

 Calyptra obovate, persistent, fissured at the apex. C.^ipsule 

 ovate or globular, exserted, pendulous, pale greenish brown, 

 protruding a little beyond the perianth, opening into about 8 

 short re volute segments or teeth. Spores smooth ; elaters Inspiral, 

 slender, attenuate at each end. Male receptacle greenish, peduncu- 

 late, produced from tlie growing point of the thallus, peltate, fiat, 

 horizontal, papillose, flesli}^ thin at the margin, crenately 8-lobed; 

 antheridia flask-shaped, imbedded in the receptacle opening- by an 

 orifice through the papillae. On the antical surface of the thallus 

 are numerous hemispherical cups with laciniate margins contain- 

 ing numerous roundish, lenticular (contracted near the middle) 

 gemmte. 



Dimensions. — Fronds 1 to 4 inches long, -3 cm.-0"8 cm. wide ; 

 peduncle 2*5 cm.-7'5 cm. high, 1 -5 mm. x r25 mm. diam. ; male 

 peduncle 2*5 cm. high ; gemmio "Go mm. x 'bb mm. ; lacinitu of 

 receptacle containing gemmae '2 mm. long. 



Hab.— By the sides of streams or in other damp and wet 

 -situations, on earth, walls or stones. Frequent in greenhouses. 

 Ver}^ common, except in the Highlands of Scotland. 



1-17, 18b. I. 



Generally distributed over Europe, Northern Asia, North 

 America, also found in Soutli Avnerica, Japan and Java. 



Obs. — One of the commonest of our frondose species and 

 easily recognised. 



For man}' of my notes and drawings of this species I am 

 indebted to a valuable paper contributed by my friend Mr. L. W. 



