238 



vol. II, pars II-, p. 342; Epicrisis, p. 271. HARVEY, W. H., Nereis Bor.- 

 Am., 1853, part II, p. 205. 



Spyridia armata Kiitz., Tabulse phycologicse, vol. XII, pi. 50, figs, c, d. 



Spyridia Berkeleyana Mont, in Exploration scientifique de PAlg4rie, 

 p. 141, pi. 15, fig. 6. 



Ceramium aculeatum Schimper in Unio itin., n. 966 (non vidi). 



var. typica (Fig. 228). 



The thallus is terete. The main filaments and branchlets are 

 corticated; the cortex consists of alternating rows of slender, 

 cylindrical cells and shorter, oblong ones ; the cylindrical cells are 

 about 55 n long and 13 // broad, the oblong cells about 40 p 

 long and 24^ broad. 



The branchlets and ramuli issue from all sides of the branches, 

 but a more or less marked tendency to distichous ramification is 

 often present in the specimens examined. At their base the 

 branches are often somewhat slender than higher up in the branch; 

 e. g. the base of a branch was 160 // broad, while higher up the 

 same branch had a breadth of 210 //. Towards their summits the 

 branches and branchlets taper evenly. 



The ramuli are broadest at their base and taper evenly up- 

 wards. They are about 1 mm. long. The basal cells in the 

 ramuli are about 100 // long and 60^ broad, in the middle of the 

 filaments only 37^ broad while their length is nearly the same. 

 At the transverse walls a whorl of small cortical cells are present. 

 The ramuli end in a mucronate tip composed of 2 cells, and 

 besides a few (one to three) uncinate spines are very often devel- 

 oped from the cortical cells below. 



HARVEY 1. c. gives a good description of this species. As 

 pointed out by this author, which my specimens confirm, the upper 

 end of the filaments is often incrassated and revolute, forming in 

 this way a hook-shaped tendril by means of which the plant is 

 able to fasten itself to other algae. The upper parts of these 

 tendrils are often more or less destitute of ramuli. 



var. disticha n. v. 



A forma typica preecipue difTert fronde plus minus regulariter 

 plumosa, ramis alternis distichis ramulisque a margine egredien- 

 tibus constructa. 



The specimens I refer to this form are especially distinguis- 

 hed from the typical one by the distichous arrangement of the 



