1900] Collins, — Marine flora of Great Duck Island, Maine 209 
Carex rigida, Gooden., Agrostis alba, L., 
var. Goodenovii, Bailey. var. vulgaris, 'Thurb. 
C. maritima, O. F. Mueller. A. alba, L., 
C. Magellanica, Lam. var. stolonifera, Vasey. 
C. flava, L. var. viridula, Bailey. Calamagrostis canadensis, Beauv. 
C. sterilis, Willd. (forms) Danthonia spicata, Beauv. 
C. canescens, L. Poa compressa, L. 
C. trisperma, Dewey. P. pratensis, L. 
C. straminea, Willd., Osmunda cinnamomea, L. 
var. aperta, Boott. 
THE MARINE FLORA OF GREAT DUCK ISLAND, ME. 
F. S. CorrLiNs. 
Tue location and character of the Duck Islands are indicated in 
another article in this number of RHopora, by Mr. Rand, with whom 
I visited Great Duck Island last July. While he was investigating the 
land flora, I gave my attention to the marine flora, and that it is 
interesting may be inferred from the fact that I did not once step 
above high-water mark, though I was among the first to land and the 
last to re-embark. The shore near the landing point shows a nearly 
horizontal stratification, with a slight upward slope seaward. There 
is thus formed a series of terraces, each with a shallow pool along its 
inner half. The bottom and sides of these pools are richly coated 
with algae, and the general development of the flora here is more 
luxuriant than on Mount Desert Island itself, even at exposed points. 
Why a small outlying island should have a more luxuriant flora than 
an exposed part of a larger island or of the mainland, it is hard to say; 
but on the New England coast, at least, this seems to be the case. 
Perhaps the most striking feature here was Ra/fsia deusta J. Ag., 
carpeting the bottoms of pools, sometimes in patches more than a 
square meter in extent. This is a characteristic northern species, its 
extreme southern limit on this coast being Nahant, Mass., and I had 
never seen it so luxuriant as here. Those who know it only from 
dried, shrunken, uniformly dark brown herbarium specimens, have no 
idea of its beauty when growing. It consists of horizontal, overlap- 
ping, fan-shaped fronds, radiately striate and concentrically zoned in 
