6 



Lithothamnion elegans Fosl. mscr. 



L. fronde libera in fundo jacente, roseo-purpurea vel roseo- 

 flavescente, decomposito-ramosa, diametro usque ad 4 cm.; ramis 

 e centro undique egredientibus, squarrosis, compressis vel subcom- 

 presso-angulatis, 1.5—2.5 mm. crassis, extremis vel dilatatis, com- 

 planato-palmatis vel subulatis, unum alterumve ramulum spines- 

 centem vel subulatum emittentibus; conceptaculis cystocarpiferis 

 convexiusculis, vix prominentibus, a superficie visis diametro 220 

 — 280 jj., demum innatis; carposporis elongato-obovatis, 50 — 70 \± 

 longis, 25 — 35 //. latis. 



f. angulata Fosl. mscr. 



f. ramis compressis vel subcompresso-angulatis, extremis ple- 

 rumque subulatis. Fig. 9. 



f. complanata Fosl. mscr. 



f. ramis inferioribus compressis vel subcompresso-angulatis, 

 extremis sæpe dilatatis, complanato-palmatis, usque 10 mm. latis, 

 1 mm. crassis, dentatis, fere spinescentibus vel subulatis, vel apiei- 

 bus interdum truncatis. Fig. 10. 



Description of the form of the spedes. Coll. Hariot No. 2. 

 I have seen but tvvo specimens, and some of the branches are 

 broken. They are nearly related to one another but on the other 

 hand ought to be specially mentioned. The one that I have named 

 f. angulata, not unlikely, constitutes the typical form of the spe- 

 des. This form is branched from the centre of the frond in a 

 rather irregular manner, its longest diameter about 4 cm., the 

 branches much spreading and more or less curved, in the lovver 

 part sorrfewhat anastomosing, either compressed or subcompressed- 

 angular, about 1.5—2.5 mm. thick and frequently rather attenuating 

 upwards. The upper branches are nearly always angular or sub- 

 compressed-angular, often subulate, seldom with a tendency to 

 divide themselves in a subpalmate manner. They here and there 

 bear one or tvvo spinescent or subulate branchlet. Cp. fig. 9. 

 The surface is smooth, here and there even feebly shining. 



The form complanata is closely connected with the former 

 artd of about the same size. It differs by its lovver branches fre- 



