CHILEAN SPECIES OF METZGERIA. 315 



Their relatively short hairs are densely crowded in the upper part 

 but more scattered below the middle. 



Although M. magellanica is undoubtedly a close relative of M. 

 hamata, as Schiffner states, it bears a strong superficial resemblance to 

 small forms of the variable M. decrescens, owing to its subterete thallus 

 with marginal hairs borne singly. Differences in the costa will at once 

 serve to separate the two species. In M. magellanica the cortical 

 cells are definitely in two rows both dorsally and ventrally, and the 

 boundary between the costa and the unistratose wings is abrupt; in 

 M . decrescens, although the cortical cells may be in only two rows both 

 dorsally and ventrally, this condition is exceptional, the number of 

 rows being usually more than two, and the boundary between the 

 costa and the unistratose wings is often gradual, the two being sepa- 

 rated by a narrow band two or three cells thick. M. decrescens is 

 further distinguished by its larger alar cells with thinner walls, and by 

 the sharp contrast in size between the cells of the vegetative thalli and 

 those of the male branches. 



11. Metzgeria hamata Lindb. 



Metzgeria linearis Lindb. Acta Soc. Sci. Fenn. 10: 494. 1875. Not M. 



linearis (Sw.) Aust. 

 Metzgeria hamata Lindb. Acta Soc. F. et Fl. Fenn. 12: 25. f. 25. 1877. 

 Metzgeria leptoneura Spruce, Trans. Bot. Soc. [Edinburgh] 15: 555. 1885. 

 Metzgeria nitida Mitt. Jour. Linn. Soc. Bot. 22: 243. 1887. 

 Metzgeria australis Steph. Hedwigia 28: 267. 1889. 



Specimens examined: Corral, 1905, Thaxter 34 (H., Y.); Huafo 

 Island, 1908, Skottsberg 253 (U., as M. albinea, and listed under this 

 name by Stephani, 24, p. 10) ; Newton Island, 1896, Dusen 113 in part 

 (B.); Punta Arenas and Tuesday Bay, Straits of Magellan, 1876, 

 Naumann (S., listed as M. linearis by Schiffner, 16, p. 42); Staten 

 Island, 1882, Spcgazzrni 65 in part (Massal., Y., 11, p. 257). The 

 material from Corral is mostly in a juvenile condition, many of the 

 thalli being narrow and etiolated and lacking costae completely. In 

 a few cases, however, the distinctive features of M. hamata are clearly 

 apparent. 



The following additional Chilean stations may be cited from the 

 literature: near Puerto Varas, Dusen (20, p. 20); Wollaston Island, 

 Hariot (2, p. 246); Hermite Island, Hooker (10, p. 27). 



The geographical distribution of M. hamata is very extensive in both 

 hemispheres. In Europe it seems to be restricted to Ireland and 

 western Great Britain with an extension northward to the Faroe 



