CERAMIACEAE. 527 



cover the apical half of the obovoid or subglobose terminal cells. The male, 

 female, and tetrasporic plants in this species have each their characteristic 

 habit and form of cell, the male plant being smaller, 1-3 inches high, with 

 lower cells cylindric-obovoid, the upper pyriform, obovoid, or subglobose. In 

 the female and tetrasporic plants the cells vary from cylindric to cylindric- 

 clavate, cylindric-obovoid, or ellipsoid; they are mostly 4-10 times as long as 

 broad in the lower parts and 1-4 times as long as broad in the upper, and 

 are moderately contracted at the septa. In all forms of G. globulifera the 

 branching is dichotomous or subdichotomous. The only Bermuda specimens 

 seen are sterile and their determination is not wholly certain. 



Griffithsia Schousboei Mont, is a smaller plant than G. globulifera, with 

 shorter and broader cells that are very strongly contracted at the septa, 

 giving the filaments a moniliform habit. The cells vary from cylindric- 

 clavate below to pyriform, ellipsoid, subglobose, and oblate-spheroid above, 

 the septal isthmi being only l~\ the maximum diameter of the cells. At the 

 apices the filaments often diminish in diameter abruptly or gradually to cells 

 -rs the diameter of the larger subjacent cells. The writer has not seen 

 antheridia in the Bermuda plants, but the species is said to have the antheridia, 

 like the tetrasporangia, in verticils at the nodes. 



Griffithsia tenuis Ag. may be recognized by its straggling habit and its 

 irregular, mostly lateral, patent or divaricate branching. The plants are 

 usually about two inches long, and most of the branches, which are commonly 

 rather few, spring from near the middle, or below the middle, of an internode. 

 In the youngest parts there are often, also, nodal verticils of very short, ex- 

 ceedingly delicate branchlets. The cells in the younger parts are 1-4 times 

 as long as broad; in the older, 3-6 times. In the younger parts the filaments 

 are often lightly contracted at the septa ; in the older, they are often swollen 

 at the septa. All specimens seen by the writer have been apparently sterile. 

 (Phyc. Bor.-Am. 1895.) 



Callithamnion corymbosum (Sin.) Lyngb. This species forms delicate 

 gelatinous rose-colored or brownish rose tufts mostly 1-3 inches high. The 

 main axes are corticated in the basal parts, the main branches are several 

 times irregularly ramified, the secondary branches are alternately pinnate 

 with dichotomo-multifid ramuli, the ultimate ramelli corymbose-fastigiaie. The 

 cells of the main axes are variable in length but are mostly 3-8 times as long 

 as broad and are often more or less enlarged just above the septum. The 

 writer is inclined to refer here specimens (sterile so far as seen) collected 

 by A. B. Hervey on various other algae at the mouth of Harrington Sound 

 and distributed (Phyc. Bor.-Am. 1896) as Callithamnion Halliae Collins, 

 from the Key West type of which (Phyc. Bor.-Am. 698) they differ in the 

 corticated main axes, the longer cells, the much more corymbose-fastigiate 

 ramelli, the frequent presence of terminal hairs, etc. 



Callithamnion cordatum B0rg. is a name that has been recently applied 

 (Phyc. Bor.-Am. 2189) to a dingy red plant 1-2 inches high found at Build- 

 ings Bay. Its ultimate ramelli are corymbose-fastigiate, somewhat as in the 



