131 



apparently provided with wart-like or short branch-like processes. 

 This unevenness is, however, at least partly caused by the sub- 

 stratum, and the excrescences are either also caused by the sub- 

 stratum, by growing over short branches or covering up small 

 extraneous objects, or, if not, they are concave in the lower part, 

 or the short branch-like processes occasionally formed are partly 

 hollow. Besides, the crust is furnished with very fine striae partly 

 radiating partly concentric not visible to the naked eye, which are 

 to be found in young as well as old individuals, in the latter, ho- 

 wever, more indistinct and partly wanting. New crusts are formed 

 upon the primary, I have seen up to three, partly rather clinging 

 to the subjacent, but seldom closely, partly more or less free and 

 but here and there adherent. 



The crust has a faint rosy colour, which by older individuals 

 frequently passes into faint brownish-yellow. Fractures of the crust 

 are rose-coloured or whitish with a rose-coloured tinge outwards. 



With regard to structure the species appears to be rather 

 var} r ing and in general agreeing with that of Eulithothamnion, . 

 sometimes, however, nearly approaching Lithophyllum. Thus the 

 basal, co-axil layer may in a thin crust be as thick or thicker than 

 the upper thickening layer, frequently, however, much thinner espe- 

 cially in thicker crusts, and is composed of rounded or somewhat 

 elongated cells about 8 — 12 p thick. The cells of the upper layer 

 are square or rectangular with more or less rounded corners, about 

 6 p- thick and up to l 1 /. 2 times longer than thick. The surface 

 cells are rounded or rounded-angular, 4 — 8 p. in diameter. 



1 have seen- but a couple of not well developed conceptacles, . 

 which apparently are those of cystocarps. They are conical, low, 

 with a single orifice and about 300 p. in diameter at the base. I, 

 however, have not seen the spores. ■ 



Relation to other species. As mentioned above the present 

 species is nearly related to L. flavescens, apparently often being 

 easily confounded with this, but the conceptacles do not grow 

 down into the frond, and it also differs in other particulars. On 

 the other side it seems to show closer affinity to L. expanswn 

 or occasionally even to coarser forms, of L. lichenoides. Cp. Hauck,. 



