The Genus Riccardia in Chile. i8i 



certain of the cells ; and both are wingless or nearly so throughout, 

 although a marginal row of cells is sometimes distinguishable. 

 The lack of stolons and the fairly regular pinnate branching in 

 R. alcicornis will at once distinguish it from R. nudimitra. There 

 are likewise histological differences. The cells of R. alcicornis, for 

 example, are unusually small, the surface-cells averaging only 12 ji* 

 in width and the interior cells only 1 7 /x ; and the wall-thickening 

 in the second and third layers is very slight: in R. nudimitra the 

 cells are somewhat larger, the surface cells averaging about 20 /x 

 in width and the interior cells about 25 /x ; and the wall-thickening 

 in the layers inside the surface-layer is usually very pronounced. 

 The resemblance of R. nudimitra to R. fuscohrunnea is still greater, 

 the latter species being much more irregular in its branching than 

 R. alcicornis. In R. fuscohrunnea, however, the cells are larger 

 than in R. nudimitra, the surface-cells being usually 22-30 /x in 

 width and the interior cells about 35 /x. There is, moreover, no 

 distinct sclerotic zone, although all the cell walls tend to be some- 

 what thickened. 



It has already been noted (see p. 100) that Stephani recorded 

 his Aneura stolonifcra from Chile in 1899. This species was 

 first described and figured from Australian material collected by 

 Kirton at "Illawarra" in New South Wales (24, p. 129, pi. 5, /. 

 i). A few years later Stephani proposed, as a new species, A. 

 striolata from New Zealand, based on one of Colenso's specimens 

 (25, p. 265, pi. 26, f. 1-3). When he revised the genus Aneura in 

 1899, he cited A. striolata as a synonym of A. stolonifera and 

 reported it from the following additional localities : Queensland, 

 Walker; "Fret. Magellan.," Cunningham ; Java, collector unknown; 

 Luzon, Sempler. The wide geographical distribution thus indi- 

 cated arouses the suspicion that he may have understood the species 

 in too broad a sense, and this suspicion is increased by some of his 

 critical remarks. In distinguishing the species he lays especial 

 stress on a peculiar lamellation of the cuticle, which he describes as 

 "dense minuteque lamellifera." His figure of A. striolata shows the 

 lamellae clearly in the form of crowded transverse bands, appearing 

 along the edge of the thallus as minute denticulations. Largely on 

 the basis of this character he refers the Queensland specimens to A. 

 stolonifera, although he admits that the internal cells are smaller 

 than in the type from Illawarra and that the thallus is noticeably 



