43 



with the conceptacles of other species, especially L. fruticulosum, 

 as they in this stage sometimes look apparently fully developed. 

 However, fully developed ones are distinctly marked and more 

 easily perceptible than in most other species, but slightly convex 

 and little prominent, the central portion or greater part of the roof 

 being frequently somewhat flattened, and traversed by 60 — 70 

 muciferous canals. 



The conceptacles finally grow down into the frond, and are 

 frequently to be found in the peripherical portion of a branch, 

 sometimes numerous and crowded, sometimes very scarce, the latter 

 probably being connected with the fact, that the roofs are thin 

 and easily dissolvable, and, therefore, often falling away, leaving 

 nearly cup-shaped scars with somewhat elevated edges. Such 

 scars occasionally become effaced by local formations of tissue, 

 and these formations again covered with a new thickening layer 

 of the frond, so that they are visible on a section as small cup- 

 shaped layers of about half the size of an overgrown conceptacle. 

 The sporangia are four-parted, about 100 — 140 fx long and 40 — 60 

 }i broad. I have seen but some few ones. 



Relation to other species. The present species on the one 

 side appears to be rather nearly related to L. fruticulosum f. fa- 

 sti giata and on the other side rather approaching L. dehiscens. 

 Younger as well as sterile specimens may be confounded with the 

 first named form. It is, however, separated thereby, that it never 

 forms lobes, the branches frequently being coarser, with longer 

 axes and less anastomosing, and the conceptacles of sporangia are 

 different. It is more easily confused with certain and younger 

 forms of L. dehiscens described below, but separated in its develop- 

 ment and other characters quoted under this species. In habit it 

 occasionally even reminds one of younger individuals of L. forni- 

 ■catum, but is separated by essential characteristics. 



A fragment of a specimen from an unknown locality kindly 

 transmittet to me by Prof. Kjellman, from oral informations sup- 

 posed by him perhaps to be identic with L. fasciculatum (Lam.) 

 Aresch., very closely accords with the species in question. It may 

 be, that this one is the same as described by Lamarck under the 



