6 M. FOSLIE, (Schwed. Südpolar-E\p. 



and zonate margin. The conceptacles of sporangia are crowded, the roofs often 

 angular, convex or flattened, subprominent, 400—700 ^i in diameter, traversed by 

 about 120 muciferous canals, sporangia tetrasporic, 130 — 200 u long and 40 — 80 u 

 broad. The conceptacles of cystocarps, which occur m other individuals than the 

 conceptacles of sporangia, are conical, 0.3 — o.s or up to i mm. in diameter. Those 

 of antheridia, also occurring in separate individuals, are s\ibconical, 200 — 300 /( in 

 diameter. 



L. fucgiaiiuin belongs to the group of species of which /,. lichenoides forms 

 the type. As far as can be judged from a scanty material, it is perhaps most 

 closely connected with L. mcsomorpliiim. It grows in the upper part of the sub- 

 litoral region on the coast of the Falkland Islands, picked up from a depth of about 

 I fathom, bearing reproductive organs in July. 



Area: Fuegia: Desolation Island: Puerto Angosto (DuSÉN); the Falkland Is- 

 lands: Berkele\- Sound, Port Louis (Skottsbekg). 



4- Lithothamnion variabile Fosl. 



Alg. Not. II (1906), J). 10; tab. no.str. i, fig. 7 — g. 



Thallus lamellate, attached to hard objects, at first forming small suborbicular 

 or subreniform crusts, becoming" more or less confluent, O.;— i mm. thick, then, by 

 repeatedly loosely overgrowing, forming i — 3 cm. thick, irregular masses, with wart- 

 like, sometimes short branchlike, e.xcrescences, or knobb)' projections. Conceptacles 

 of sporangia convex or flattened, but little prominent, 400 — 600 f( in diameter. 



The specimens brought home of this species are not well developed and rather 

 varying in habit. There are apparently two forms, which, however, are no doubt 

 representing the same species. One of them is composed of very small lamels, which 

 are subcircular or subreniform, finall\- somewhat confluent, with small wartlike ex- 

 crescences, the other more crustily expanding with coarser, knobb)' or irregular pro- 

 jections. The lower part of the specimens is mostly dead, in the upper, living part 

 a constant overgrowing of foreign bodies takes place, with which the alga is much 

 encumbered. It partly grows on other alga-, e. g. Lithopli. falkla)idicum. 



In a section the h\-pothallium is mosth- vigoroush' developed, and the peri- 

 thallium is stratified. The cells of the latter are rather thick-walled, mostly vertically 

 elongated I's or up to twice the breadth, the length being 10 — 14 ,"> occasionally 

 up to 18 II, and the breadth being 9 — 11 u. 



The conceptacles of sporangia occur scantil}- and in small groups. Thé roof is 

 intersected with about 90 muciferous canals. A few conceptacles examined were 

 attacked by animals and had no sporangia. 



