H^EMATOCOCCUS. 329 



specimen of a dark olive compact substance two inches in ex- 

 tent, marked Tremella. This, on examining with the micro- 

 scope, I soon ascertained to belong to the present genus, of 

 which it forms a remarkable species one remarkable for the 

 size of the vesicles, the smallness of the enclosed granules, and 

 for the absence in general of concentric rings or vesicles. 



** Granules mostly numerous in each cell. 

 9. HZBMATOCOCCUS SANGUINEUS Ag. 



Plate LXXIX. Fig. 2. 



Char. Smaller cells spherical, containing usually one or two 

 granules ; larger, often angular, and filled with numer- 

 ous blood-red, circular, and nucleated, granules. 



Hamatococcus sanguineus Ag., Icon. Alg. Europ. No. xxiv. 

 Palmella ? sanguinea Ag., Syst. p. 15. ffcem. sangui- 

 neus, in part, Harv. Manual, p. 181. 



Hob. On shady rocks at Tobermorey in Mull: W. H. 

 Harvey. 



Mr. Harvey in his " Manual " has included in his Hcemato- 

 coccus sanguineus two species, the one being the Palmella? 

 cryptophila of Carmichael, the other, in all probability, the 

 true H. sanguineus, a production which would seem to be as 

 rare as it is strikingly beautiful, it only having as yet been 

 discovered in one locality by Mr. Harvey, to whom I am in- 

 debted for the specimen from which my figure is taken. The 

 smaller cells are quite spherical, and contain but a single 

 blood-red granule, a wide pellucid border produced by the 

 thickness of the single vesicle which encloses it surrounding 

 the granule: the larger attain a very considerable size, are 

 mostly angular, and include a very considerable number of 

 large spherical granules, each of which is occasionally sur- 

 rounded by a transparent vesicle, in which state each separate 

 granule is to be regarded as a distinct young frond enclosed 

 in the parent cell. 



