574 



ALEXANDER W. EVANS 



of a marginal cell. The narrow wings have a width of three to five cells and 

 are naked, but the thickened median portion is often more or less densely pilose. 

 The hairs are straight or nearly so. 



Area of distribution: South Chile; Masafuera. 



*i5. M. decipiens (Massal.) Schiffn. & Gottsche, in Schiffner, Forsch- 

 ungsreise »Gazelle» 4*: 43 (1890); Evans, Proc. Amer. Acad. 58: 296 f. 6, 7 

 (1923). — M. fnrcata [3 decipiens Massal. Nuovo Gior. Bot. Ital. 17:256 pi. 

 28 f. 36 (1885); M. glabeninia Steph. Bull. Herb. Boissier 7:939 (1899). 



On bark of trees. 



Masatierra: V. Colonial, Q. seca, on Fagara, 435 m. (no. 47); Q. de la 

 Choza, on trunks, 250 m. (no. 48). 



Masafuera: O. del Mono, on base of Myrceiigenia, 440 m. (no. 49). 



The characteristics of this widely distributed and variable antarctic species 

 have recently been discussed by the writer. It is distinguished by its plane or 

 slightly convex thallus, by the frequent occurrence of ventral branches, by its 

 costa bounded both above and below by two rows of cortical cells, by a lack 

 of hairs on the surface of the wings, by its marginal hairs usually borne singly 

 and often scantily produced, by its dioicous inflorescence, and by a total lack 

 of gemmae. It shows, moreover, a marked tendency to revert to more juvenile 

 conditions, narrow unistratose conditions being not uncommon. The Juan Fer- 

 nandez specimens agree closely with those from Chile; the material from Masa- 

 tierra seems to be entirely sterile, but the Masafuera plants show both male 

 and female branches in considerable abundance, a few of the latter bearing 

 calyptras with well-advanced sporophytes. 



Area of distribution: South Chile; Australia; New Zealand; Masafuera. 



*i6. M. multiformis nov. spec. '■ — Fig. 5. 



Pale green, often turning whitish upon drying, scattered or growing in 

 thin depressed mats, loosely adherent to the substratum or free; thallus pros- 

 trate, sparingly dichotomous and frequently branching ventrally, plane or very 

 slightly convex, well-developed thalli mostly i — 1.5 cm. long and 0.9 — 1.2 mm. 

 wide, the forks usually i cm. or more apart but sometimes only 2 — 6 mm.; 

 costa bounded both dorsally and ventrally by two rows of cortical cells, often 

 poorly developed or absent altogether; wings mostly twelve to sixteen cells 

 broad, the cells averaging about 43 X 37 [x, thin- walled throughout or with 

 minute and indistinct trigones; hairs restricted to the margin and ventral sur- 

 face of costa, varying greatly in abundance and sometimes very sparingly pro- 

 duced, marginal hairs borne singly, mostly 0. 1—0.3 mm. long and 12 — 18 \i. wide, 

 often slightly displaced to the ventral surface and sometimes branched at the 

 tip and acting as rhizoids, straight or irregularly curved or contorted: inflorescence 

 dioicous: J* branches not seen: $ branches sometimes fairly abundant, broadly 

 obcordate, mostly o 25 — 0.3 mm. long and 0.35-0 45 mm. wide, slightly concave 

 (from above), hairs abundant along the margin and representing the prolongation 

 of marginal cells, otherwise scanty and restricted to the ventral surface of the 



