192 Rhodora [NOVEMBER 
cluster is perhaps thus to be explained. But there is evidence that 
the glabrate plant grew on Nantucket long before any effort had been 
made to introduce the heather there. The Herbarium of Columbia 
University contains another old specimen of Calluna labeled simply 
“Nantucket” without other record. It belongs among the earlier 
collections of the heather on that island and is of the glabrate form. 
It would seem to be most unlikely that both forms had come to the 
island together from the same place in Europe, and it is therefore to 
be inferred that Nantucket has received this addition to its flora from 
at least two sources of origin. Indeed Mrs. Owen believes (loc. cit.) 
that a solitary plant of Calluna found on Nantucket in 1880 far away 
from the locality where it was brought in with European conifers 
three years before was not of that introduction. How it came there 
is not less a mystery than is the presence of the heather at the other 
widely separated localities from Newfoundland to New Jersey where 
it has been found on the American Continent. 
New York Crry. 
TWO NEW SPECIES OF STIGONEMA.! 
FRANK N. BLANCHARD. 
(Plate 105.) 
In some material collected in October, 1909, by Dr. F. D. Lambert 
of Tufts College, from Chebacco Pond in the town of Essex, Essex 
County, Massachusetts, there was found very abundantly a blue-green 
alga, that apparently had not been described before, belonging to the 
family Stigonemaceae. This material was put into formalin and left 
until November, 1912, when Dr. Lambert and myself secured fresh 
material from the same place and found the same alga still plentiful. 
In April, 1913, I visited the pond and found the alga very scarce, but 
in exactly the same growing condition as in the previous November. 
It was found free-floating among other algae, chiefly blue-greens, 
where dead leaves and stems had collected in masses at the edge of the 
pond. Its filaments form loose, wiry-looking clusters from: one to 
several millimeters in diameter. 
1 Contributions from the Biological Laboratories of Tufts College, No. 55. 
