THE MAEINE ALGiE OF NEW ENGLAND. 27 



colonies. Intercellular substance generally forming concentric 



layers around the cells Glceocapsa^ 



3. Cells united in colonies of definite shape. 



%. Cells arranged in the form of an irregular sphere, which becomes 

 finally hollow and net-shaped GlatJirocystis. 



b. Cells arranged in several layers forming a solid spheroidal body. 



Polycystis. 



c. Cells united in branching dendritic masses Entophysalis. 



CHROOCOCCUS, Nseg. 



((From XP°°C) *h e color of the body, and kokkoc, a berry.) 



Cell division taking place in all directions, cells spherical, solitary, 

 or united in twos or some multiple of two, free, *. e., not united into 

 families by means of an intercellular substance. 



According to Nsegeli, the principal distinction between Chroococcus and Glceocapsa 

 lies in the fact that in the former genus the cell-wall is thin, while in the latter it is 

 thick and formed of concentric layers. This difference, however, is not constant, as in 

 Chroococcus turgidm the cell- wall is comparatively thick, whereas in Glceocapsa crcpi- 

 dinum the cell-wall is reduced to a minimum. A more characteristic distinction seems 

 rather to be the existence of an intercellular substance in Glceocapsa which binds the 

 cells together, but which is wanting in Chroococcus. 



C. tubgedus, STseg. (Protococcus, Kiitz., Tab. Phyc, Yol. I, PI. 6, 

 Fig. 1. — Scematococcus binalis, Hassal, Fresh-water Algae, p. 331, PI. 

 82, Fig. 2.) 



Cells bluish green, oval, usually single or binate, about .02 mm to 

 .025 mm in diameter, surrounded by a thick cell-wall. 



Cape Ann, Mrs. A. L. Davis; Europe. Fresh water and marine. 



Found on slimy rocks and piers upon which species of Calothrix, Lyngbya, &c, are 

 growing. Probably common throughout New England. The size of the cells varies 

 very much. What we have given above is an average measurement. 



GLCEOCAPSA, (Kiitz.) Nseg. 



(From yloLog, sticky, and Kaipa, a box.) 



Cell division taking place in all directions, cells spherical, with thick 

 walls, solitary or united in families, which are surrounded by a gelatin- 

 ous substance which is generally in concentric layers around the cells. 

 Spores known only in G. stegopliila, Itzigs. (G. Itzigsohnii, Bornet mscr.). 



This genus, if we adopt the views of the advocates of Schwendener's theory, forms 

 the gonidia of the lichen genera SynaUssa, Omplialaria, &c. 



G-. ceepedinum, Thuret, Notes Algologiques, p. 2, PL I, Figs. 1-3. 

 (Protococcus, Thuret, in Mem. Soc. Natur. Cherbourg, Vol. II, p. 38S j 

 Le Jolis, Liste des Algues Marines de Cherbourg, p. 25 j Farlow, List 



