164 Rhodora [AUGUST 
'The plant which in northern New England has passed largely for 
JD. foeniculaceus appears to be rather D. Aispidus Kjellm. In gen- 
eral habit it is not unlike the older species ; the branching is abundant 
and pretty regularly alternate, and the younger parts are uniformly 
beset, often quite densely, with subulate or filiform ramuli, two or three 
cm. long. These appear to be of a distinct class from the normal 
branches, and of limited growth, remaining of the same dimensions, 
while normal branches continue to grow and branch indefinitely. 
The writer has collected this species at various points from Nahant, 
Mass., to Mount Desert, Maine, and it probably continues along the 
Canadian shore, as it occurs in Greenland, Spitzbergen and Norway. 
It seems to prefer rocky pools on rather exposed coasts, and grows 
by preference on Chordaria flagelliformis (Fl. Dan.) Ag. It is in its 
best condition in July and August. 
D. hippuroides (Lyng.) Kuetz, like the last species, has often 
passed under the name of D. foeniculaceus, and it must be confessed 
that it is not easy to distinguish the two. D. Aippuroides is a coarser 
plant, less branched, the branches of various orders more nearly of 
the same size and less tapering. Our plant, as compared with the 
European forms, is of looser structure, and has a larger central cavity. 
It is our largest species, and in favorable situations may reach a meter 
in length. What appears to be a reduced form, not over a decimeter 
in height, is found at Newport, R. I. (Mrs. Simmons). There is no 
other record of its occurrence south of Nahant, but from that point 
north it is common, usually growing on Chordaria flagelliformis, occa- 
sionally on other algae. 
D. ùippuroides var. fragilis (Harv.) Kjellman, has the branches 
of the first order of nearly the same diameter throughout, except at 
the base, where they are distinctly constricted; branches of higher 
order than the first are few ; the general habit is that of the subgenus 
Coilonema, and extreme forms also resemble D. Macounii Farlow. 
It is common at Marblehead Neck, Mass., in company with the type, 
both on Chordaria flagelliformis. 
In the typical form of D. Macounii Farlow there is a stout main 
axis like a Scytosiphon, and similarly hollow ; from this issue numer- 
ous branches of nearly uniform length, and seldom divided or branched ; 
they aie either straight or incurved, and taper to both ends. This 
form occurs in the Gulf of St. Lawrence; only a reduced form, ap- 
proximating D. Aippuroides, occurring in New England. This was 
