THE MARINE AL>GM OF NEW ENGLAND. 27 



colonies. Intercellular substance generally forming concentric 



layers around the cells Glococapsa. 



3. Cells united in colonies of definite shape. 

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

 fiually hollow and net-shaped Clathrocystls. 



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



PolycysUs. 



c. Cells united in branching dendritic masses EntopUysalis. 



CHROOCOCCUS, Na3g. 



((From ^poof, the 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 NsBgeli, the principal distinction between Chroococcus and Glococapsa 

 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 turgidus the cell- wall is comparatively thick, whereas in Glococapsa crcpi- 

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

 rather to bo the existence of an intercellular substance in Glococapsa which binds the 

 cells together, but which is wanting in Chroococcus. 



C. turgidus, Noeg. (Protococcus, Kiitz., Tab. Phyc, Vol. I, PI. G, 

 Fig. 1. — Uccmatococcus binalis 1 Hassal, Fresh-water Algce, 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 Caloihrix, Lyngbya, &c, are 

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

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



GIXEOCAPSA, (Kiitz.) Nreg. 



(From ylowg, sticky, and naipa, 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. stcgophila, Itzigs. (G. Itzigsohnii, Bornet mscr.). 



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

 the gonidia of the lichen genera Synalissa, Omphularia, &c. 



G. crepidinum, Thuret, Notes Algologiques, p. 2, PI. I, Figs. 1-3. 

 (Protococcus, Thuret, in Mem. Soc. Natur. Cherbourg, Vol. II, p. 388; 

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



