A MONTH ON THE SHORES OF MONTEREY BAY. 65 
The surrounding rocks are left by the ebbing tide covered 
with a dense moist mat of the olive-green weeds, which are 
interesting, though possessing little beauty in form and color. 
Three species of Fucus are represented here. Fucus fastig- 
iatus and F. Harveyanus are perhaps the most abundant, 
though F’. evanescens is not rare. Fucus fastigiatus, when 
growing at about the point reached by the highest tides has 
a peculiar dwarfed aspect which is quite striking. They 
were doubtless specimens from such a locality to which 
Harvey alludes in the Nereis as having been collected at 
Monterey by Douglas. Ascophyllum nodosum, so common 
on the Atlantic coast, is conspicuous by its absence, but its 
place is taken, in a way, by Codiwm tomentosum, which does 
not favor New England with its presence though found on 
almost every other shore in the world. 
Halidrys osmundacea, or Sea-oak, is an interesting 
plant growing at low-tide mark and below, which I regret 
not giving more attention. The fronds of the few specimens 
secured are remarkably variable, and moreover they are 
strictly dicecious, though Harvey gives “spore-cavities con- 
taining both spores and antheridia in the same loculus” as 
a generic character both of Halidrys and Cystoseira. The 
fragment of a plant described by Harvey, first in the Botany 
of Beechey’s Voyage as Cystoseira Douglasit and afterward 
referred in the Nereis to the C. expansa of J. Agardh, is 
thought by American phycologists to have been simply the 
upper part of the deep water form of Halidrys osmundacea. 
It is possible that the forms now going under the name of 
H. osmundacea are in need of further study on their native 
rocks. 
Halosaccion Hydrophora, often popularly called Sea- 
sacks, is not uncommon in the lower tide-pools near Pacific 
Grove. The fronds of this species are described in the 
Nereis as “quite simple,” but specimens were here found 
with conspicuous proliferous branches. One of the note- 
worthy features of the Pacific marine fipra when compared 
with that of the Atlantic is the striking exhibition of the 
