196 _ MISSOURI BOTANICAL GARDEN. 
size differ somewhat from the common form of B. Braunii which 
occurs in the United States. The size of the individual cells, 
11-13 » < 7-9 #, however, indicates that the alga should be 
regarded rather as a coarse form of B. Braunii than a form of 
B. gigantea, Reinsch, of South Africa, in which the dimensions of 
the cells are given as considerably larger. 
Urococcus HookertAnvs, Kiitz. 
Flores (1458). 
The specimens here referred to this species form small gelatinous 
masses which in their microscopic structure bear a considerable 
resemblance to Hormotila mucigena, Borzi. The average diameter 
of the cells, not including the gelatinous walls, is 84, The absence 
of any unstriated mucilaginous stalks, however, points rather to 
the genus Urococcus, and the present plant agrees so well with an 
authentic specimen of U. Hookerianus, for which I am indebted 
to Dr. Ed. Bornet, that, in spite of the color of the cell contents 
which are deep grass-green rather than red, it can be referred to 
that species without much doubt. A point of more importance is 
that the alga of the Azores was collected in salt or, at least, brack- 
ish water, while the original specimens of U. Hookerianus grew in 
fresh water. The species has also been reported by Borzi, in 
Malpighia. 1: 137, as occurring in Sicily, but it is not stated 
whether in fresh water or marine. JU. Foslieanus, Hansg., Trom- 
soe Museums Aarsheft. 183 156, agrees with the Azores alga in 
being marine and having green rather than red cell contents, but 
differs in having cells which are from 15-25 » in diameter. 
DicryrospHarRiIuM Exnrenspercianum, Nig. Archer 329. 
San Miguel. 
TETRASPORA, sp. 
Terceira (1434 ).— Fragmentary. 
TETRAEDRON TETRAGONUM, Hansg. Polyedrium tetrago- 
num, Archer 329. 
San Miguel. 
ScENEDESMUS OBLIQUUS, Kiitz. S. acutus, Archer 329. 
San Miguel. 
S. nuuaeatus, Kitz. S. obtusus, Archer 329. 
San Miguel. 
S. quapRIcAUDA, Breb. Archer 329. 
San Miguel. 
PrpiastruM Boryanum, Menegh., var. GRANULATUM, Br. 
P. granulatum, Archer, 329. 
San Miguel. 
