6 M. FOSLIE. [1900 



frequently rounded, 4 — 7 /j. in diameter, apparently seldom also 

 sending a very feeble layer downwards. 



The conceptacles of sporangia are more or less crovvded in 

 any part except the peripherical portions, convex, subprominent, 

 not or but now and' then sharply defined, often rather indistinct, 

 350 — 600 p- in diameter seen from above. On a median vertical 

 section they are shown to be up to 750 /j- in diameter. The roof 

 is intersected with a number of scattered muciferous canals. The 

 sporangia are four-parted, 100 — 140 p- long by 60 /->-, with enduring 

 inter walls. 



The present species separates itself from L. lichenoides especi- 

 ally with reference to the conceptacles of sporangia and in structure. 



It is only known from Bermuda, herb. W. G. Farlow, no. XI. 



L, syntrophicum Fosl. mscr. 



Thallus crustlike or lamellate, rather closely surrounding other 

 calcareous Algæ or divers other objects, new lamels repeatedly 

 formed over each other, irregularly and loosely clinging to the 

 subjacent, 200 — 800 fi thick, forming at length small and irregular, 

 knotty nodules. Conceptacles of sporangia convex, subprominent, 

 400 — 600 ;j- in diameter. 



The species surrounds fragments of other calcareous Algæ, 

 tubes of divers animals and other objects. The specimens seen are 

 but 2 — 3 cm. in diameter and not quite entire, but appear to have 

 been ly ing loose at the bottom. 



On the one side it rather resembles L. Philippii in appearance 

 and on the other hand closely allied to L mesomorphum. In fact 

 it appears to stand in the same relation to the latter as L. Philippii 

 to L. lichenoides, although the specimens at hand more approach 

 L. mesomorphum than the mutual connection ever is to be seen 

 between L. Philippii and L. lichenoides. However, in habit it 

 only approaches such specimens of L. mesomorphum which are 

 burdened with other Algæ or extraneous objects giving rise to a 

 more irregular development than in typical specimens. Therefore, 

 ' I consider it a separate species somewhat differing in structure too. 



The hypothallic layer is composed of cells which are more or 



