METZGERIACKAE. 



465 



2. Riccardia multifida (L.) S. F. Gray. 

 Cleft Eiccardia. (Fig. 500.) Thallus 

 mostly 5"-15" long, regularly bipinnate or 

 tripinnate, the branches about 5" wide, 

 uniform in width or slightly tapering toward 

 the apex, thinning out to a crenulate margin 

 one cell thick and two or three cells wide. 

 Inflorescence autoecious; ring-like thicken- 

 ings present in outer layer of capsule wall, 

 absent from inner layer. [Jungermannia 

 multifida L.] 



On moist soil in swamps. Devonshire and 

 Paget marshes. Widely distributed in Europe, 

 Asia, and North America. 



2. METZGERIA Baddi. 

 Thallus pale green, linear, apparently 

 regularly dichotomous, composed of a median 

 strand of elongated cells surrounded by a 

 single layer of enlarged cortical cells and 

 bounded on each side by a broad wing one 

 cell thick; unicellular hairs usually present. 

 Antheridia borne on short ventral circinate 



branches with involute margins and distinct midribs. Archegonia borne on 

 short ventral branches without a distinct midrib. Calyptra obovoid or clavate 

 with numerous hairs. Pseudoperianth none. Capsule spherical, the wall 

 splitting into four equal valves two cells thick, their walls without ring-like 

 thickenings. Elaters usually with a single band of thickening, remaining 



attached to the free tips of the valves. 

 Gemmae discoid, with or without mid- 

 ribs, borne on the margin or upper surface 

 of the thallus. [Commemorates .Johann 

 Metzger, German horticulturist.] About 75 

 species, mostly tropical. Type species: M. 

 furcaia (L.) Dumort. 



1. Metzgeria conjugata Lindb. Metz- 

 GERIA. (Fig. 501.) Growing in depressed 

 mats, green, varying to yellowish green. 

 Thallus about 1" wide and 10"-15" long, 

 repeatedly forking, plane or somewhat con- 

 vex, the midrib bounded above by two 

 longitudinal rows of cortical cells, below 

 by four; hairs borne on the margin, the 

 lower surface of the midrib, and (occa- 

 sionally) the lower surface of the wings, 

 the marginal hairs usually in pairs; intlo- 

 rescence autoecious; gemmae apparently 

 none. 



On rocks. Thurch Pave and WalsinRham. 

 Almost cosmopolitan. The Bermuda specimens 

 are sterile and not quite characteristic, and 

 their reference to the present species is there- 

 fore doubtful. 



