44 



vaya Zemlya (Kjellman); the coast of Russian Lapland (Gobi);; 

 Greenland (Rosenvinge); Iceland (Stromfelt). 



Lithothamnion breviaxe Fosl. mscr. 



L. fronde initio plerumque circum lapides vel conchas effusa(?),. 

 demum libera in fundo jacente, diametro usque 20 cm., irregu- 

 lariter subdichotome ramosa, ramis brevibus, confertis, subcylindri- 

 cis, 2 mm. crassis, plus minus coalitis, parte superiore uno alterove 

 ramulo brevissimo, verrucæformi sæpe præditis, apicibus obtusis; 

 conceptaculis sporangiferis convexiusculis at parum prominentibus, 

 diametro a superficie visa 350 — 450 //; conceptaculis cystocarpi- 

 feris depresso-conicis, diametro 400 — 500 /*. Sporangiis quaternas 

 sporas foventibus, circa 160 /x longis, 45 /* latis. Tab. 2. 



Description of the spedes. Of this plant I have seen but an 

 old specimen, and a younger one probably belonging to the same 

 form, and besides I met with some few others anastomosing with 

 a form of L. glaciale. However, this anastomose was in most 

 cases so thoroughly, that any limit is impossible to draw especially 

 in the central or lower part of the plants. Pl. 2, fig. 2. The 

 named younger specimen appears not to have been fastened to 

 any harder object, subglobose and branched from the centre, but 

 here the branches rather anastomosed in an apparently early stage 

 of development. The otber and old specimen appears to have at 

 least in part encompassed a stone or another object, which later 

 is fallen out. It is about 22 cm. long, 15 cm. broad at the broadest 

 part and 8 — 10 cm. in thickness. Pl. 2, fig. 1. It is in part 

 somewhat hoilow, and has apparently at first been provided with 

 a thinner crustlike hypothallus, but shows in an older stage only 

 here and there a tendency to continue a crustlike development of 

 this hypothallus, or is in part rather rubbed. The specimen is 

 branched in an irregular subdichotomous or trichotome manner, 

 with very short axes. The branches are densely crowded in the 

 upper part as well as in that turning towards the bottom, sub- 

 cylindrical and about 2 mm. thick, partly rather straight partly 

 somewhat bent and frequently fastigiate, and the ends as a rule 



