OF C'liETAC'EOUS PLANTS. 



20 1 



• , . ; 



Text-lig. l(i. — Lithot/iamnium Gu/Jfiissi, Giliubel. External form. 

 Katurnl size. 



)& 

 fe 



Text-fig. 17. — Lithothamniicm ccnomavicuvi, Eotliplelz. A. External 

 appearance, natural size. B. Cross eection showing a zone uf 

 tetraspore deTelopnient, X 2 After Eotlipletz. 



