1903] Yukon Hepatic.^. ic 



Macoun at Lake Manitoba and in the Rocky Mountains of 

 British Columbia. 



MESOPTVCHIA, (Lindb.) gen. nov. 

 Jungermannm, B. Eujungermanyiia, b Mesoptychia, Lindb.; 

 Lindb. & Arnell, Konor|. Sv. Vet. Akad. Handl. 23^ • ,q' 

 1889. ' ^^' 



Lophosia, nuhgQnyis Mesoptychia, SchiflFn.; Bngler & Prantl, Die 

 natiirl. Prtanzenfam, i^ :85. 1893. 



Stem simple or sparingly branched, sometimes with sub- 

 floral innovations : rhizoids numerous : leaves alternate 

 succubous, more or less deeply bilobed and longitudinally 

 folded at about the middle ; antical lobe convex ; posticai 

 lobe concave ; underleaves deeply bifid with ciliate divisions: 

 leaf cells with distinct trigones and verruculose cuticle :' 

 9 inflorescence terminal on a stem or leading branch ; bracts 

 and bracteoles similar to the leaves and underleaves, more or 

 less adnate to the perigynium ; perianth free with two 

 rounded lateral keels and a sharper antical keel {i.e. epigoni- 

 anthous), contracted and short-ciliate at the mouth ; peri- 

 gynium penJent at right angles to the axis, cylindrical, with 

 numerous scattered rhizoids, smooth inside ; calyptra fleshy, 

 covering the whole of the sporophyte except the foot and 

 bearinjr the unfertilized archegonia at its base : ^ inflor- 

 escence intercalary on a stem or leacing branch ; bracts 

 similar to the leaves but often with a small tooth-like or sac- 

 like lobe at antical base ; paraphyses (when present) in the 

 form of minute filamentous or subulate hairs ; bracteoles 

 similai to the underleaves : young sporophyte of the ordinary 

 jungermanniaceous type, divided into capsule, stalk and foot, 

 the last being bluntly conical and extending around the base 

 of the stalk as a narrow collar; mature capsule unknown. 



8. MESOPTVCHIA SAHLBERGII, (Lindb. & Arnell). 

 Jungermannia Sahlbergii, Lindb. & Arnell, /. c. 40. 

 LopJwzia Sahlbergit, Schift'n. /. c. 85. 



Robust, brownish-green or reddish, growing in loose 

 tufts: stems slightly flattened, 0.8mm. wide, 0.4mm. thick 



