F. Børgesen: List of species. 461 



66. Lithothamnion ruptile Foslie. 



67. — occidentale Foslie. 



68. Lithophyllum accretum (Fosl. et Howe) Lem. 



69. — caribaeum Fosl. 



70. — erosum Fosl. 



71. — intermedium Fosl. 



72. — daedalum Fosl. et Howe. 



73. — strictum (Fosl.) Lem. 



var. nana Fosl. et Howe. 



74. — absimile Fosl. et Howe. 



75. — (?) propinquum (Fosl.) 



76. — - prototypum Fosl. 



77. Melobesia farinosa Lamx. 



78. — Chamaedoris Fosl. et Howe. 



79. — atlantica (Fosl.) Lem. 



80. — affinis (Fosl.) Lem. 



81. Porolithon mamillare (Harv.) Lem, 



var. occidentalis Fosl. 



82. — Boergesenii (Fosl.) Lem. 



83. — pachydermum Fosl. 



84. Amphiroa rigida Lamx. 



85. — fragilissima (L.) Lamx, 



86. Corallina cubensis (Mont.) Kütz. 



87. Jania pumila Lamx, 



88. — adhaerens Lamx. 



89. — decussato-diehotoma Yendo. 



90. — capillacea Harv. 



91. — spec. 



92. Spermothamnion investiens (Crouan) Vickers. 



var. cidaricola Børgs. 



Besides the var, cidaricola (comp, p. 200), which covers the 

 spikes of Eiicidaris tribuloides quite densely, I have come across 

 a closely related form which in a similar way may densely cover 

 the stems of Chamædoris Peniculum to which it is fastened firmly 

 by means of the numerous short rhizoids given off from the basal 

 creeping filaments (Fig, 422 a). The rhizoids are unicellular, end- 

 ing in a broad disc with coralliform outline. The creeping filaments 

 are upto 35 ^ thick. 



