28o Alexander W. Evans, 



of his figures show six, four, or only three lobes. Stephani 

 places the number at about eight in his account of M. disjunct a 

 but makes no mention of the male receptacles in M. domingensis, 

 M. Elliottii or M. caracensis. Apparently a good deal of varia- 

 tion is to be expected from varying environmental conditions, as 

 Goebel^^ has recently noted, poorly developed material showing a 

 reduced number of lobes. Even when only two rays are present 

 the upper part of the stalk shows two rhizoid-furrows, although 

 the lower part shows but one. The deeply lobed male receptacle 

 will distinguish M. domingensis from all the preceding species 

 except M. hrevUoha. In addition to its greater size this species 

 differs from M. domingensis in the appendages of the ventral 

 scales, which are larger and much less toothed ; in the slime cells 

 of the thallus, these structures being apparently never found in 

 M. domingensis; in the less deeply lobed female receptacles ; and 

 in the distinctly ciliate involucres. 



7. Marchantia papillata Raddi 



Marchantia papillata a brasiliensis Raddi, Mem. Soc. Ital. Modena 



19 : 44. 1823 ; 20: pi 6a, f. 3, 4. 1829. 

 Marchantia platycnemos Schwaegr. ; Gaudichaud, Freyc. Voy. 



Bot. 218. 1827 (as to the BraziHan plant). 

 Marchantia androgyna Nees ; Martius, Fl. Brasil. i : 308. 1833. 



NotL. 

 Marchantia subandina Spruce, Trans. Bot. Soc. Edinburgh 



15:561. 1885. 



Thallus dull green, not glaucous, sometimes more or less pig- 

 mented with purple, usually 1.5-3 "^^i"- wide and 0.8-1. 15 cm. 

 long, dichotomous, the forks usually only 1.5-3 ^^- apart, texture 

 firm, margin entire; epidermis composed of cells with more 

 or less thickened walls, usually in a single layer, mostly 20-50/x 

 long (averaging about 30/x) and i2-20fM wide (averaging about 

 15/^) > papillae absent; pores (with their surrounding cells) 

 mostly 50-70/* long and 40-45/* wide, surrounded usually by five 

 (or six) rows of cells (two or three in the upper series and three 

 in the lower series), each row usually composed of four cells 

 (rarely of three or five), the lowest row of the upper series 

 sometimes with from five to eight cells, inner opening usually 

 four-sided (rarely with three or five sides), the sides concave, 



'^ Organographie der Pflanzen, 26. ed. 699. 1915. 



