330 PKOTOCOCCE^:. 



10. H^MATOCOCCUS FRU8TULOSUS Harv. 



Plate LXXXI. Fig. 1. 



Char. Crust widely spreading, friable, dark grey. Cells large, 

 roundish, containing numerous, very minute, scattered 

 granules. 



Palmella frustulosa Carm., MSS. cum icone. Hcematococ- 

 cus frustulosus Harv., in Hook. Br. Fl. p. 395. ; also in 

 Manual, p. 181. 



Hab. On irrigated cliffs, perennial, Appin : Capt. Car- 

 michael. 



Capt. Carmichael thus briefly describes this fine species : 

 " It occurs in the form of a greyish black fragmentary scurf 

 On the slightest pressure it separates into corpuscles of va- 

 rious forms, but mostly spherical, hyaline : under the micro- 

 scope, surrounded by a membranous envelope, and including 

 several granules." 



The granules are very minute, spherical, not usually sur- 

 rounded by vesicles, and very numerous, the larger cells en- 

 closing as many as one or two hundred granules. 



11. H^MATOCOCCUS ARENAEIU8 HttSS. 



Plate LXXVI. Fig. 10. 



Char. Cells spherical, rather small, containing spherical 

 green granules, varying in number from one to ten, but 

 usually there are five or six. 



Hab. Tunbridge Wells Common : Mr. Jenner. 



This species approaches rather closely to the preceding, but 

 yet may be easily distinguished from it. The cells or fronds 

 of H. arenarius are much smaller, contain fewer granules, 

 although these are larger than those of H. frustulosus. 



*** Granules frequently binate or quaternate. 



The granules in all the species of the genus Hcematococcus 

 are increased by division, the division not usually extending 



