144 Rhodora [JULY 
shown by De la Pylaie's figure (1824, pl. 9, f. L). It is very close 
to Z. Gunneri Foslie of the Norwegian coast. 
2. L. DIGITATA (L.) Edm. The stipe in this species is stout and 
rigid, so that it remains erect under the weight of the blade even 
when the plant is left wholly or partially exposed by the recession of 
the tide. It is also decidedly compressed above in all its forms, and 
especially in the forma complanata. In these two characters are to 
be found the distinguishing features of the species, at least as far as 
the New England forms are concerned. A number of forms, pre- 
sumably environmental, have been distinguished, most of which are 
to be found within our limits. The species is abundant north of 
Cape Cod, and occurs at certain exposed points to the south of it. 
f. rvPICA Foslie. In its most characteristic and easily recognized 
state, f. /y^iva is a fairly large plant, with stipe long proportional to 
the blade, the base of the blade distinctly or even extremely cordate, 
and the divisions of the blade many and narrow. Foslie gives a 
characteristic figure of f. ¢ypzca (1884, pl. 4, f. 1). The stipe is usu- 
ally longer than the blade, but not always so; and while decidedly 
compressed above, is not so flattened as is the case in f. complanata. 
The base is usually heart-shaped, but is at times decidedly cuneate, 
especially in the plants from the south of Cape Cod. ‘This form 
occupies the sublittoral and perhaps also the elittoral zone, seldom 
reaching that part of the sublitoral zone near the lower limit of the 
tides. It is common from Nahant northward, being cast ashore in 
great quantity on all the northern beaches. It is the only form of 
L. digitata which, to the writer's knowledge, passes Cape Cod to the 
southward. It is found cast ashore at such exposed points as Gay 
Head on Martha's Vineyard and Watch Hill, R. I., and comes ashore 
also in great quantity at New London, Conn. The writer has found 
plants of reduced size and cuneate base growing on piles on the 
* Ocean Pier " at Watch Hill. 
f. COMPLANATA Kjellman. This form is to be distinguished from 
the preceding by its uniformly large size, and especially by the very 
decided flattening of the stipe just underneath the base of the blade. 
Kjellman’s figures (1877, pl. 1, f. 14-18) show well the extent of 
this flattening. Kjellman’s most striking example had the stipe 7.5 
centimeters broad just below the transition place, and only o.5 centi- 
meters thick. The writer has seen specimens on the New England 
coast of measurements closely approximating these. The f. comp/anata 
is evidently a form of the deep waters, and has been found cast ashore 
at Nahant Beach, near Lynn, Mass., and on ocean beaches on Peak's 
Island, near Portland, Maine. 
f. ENSIFOLIA Le Jolis. The stipe of this form is shorter than the 
blade and usually more or less curved. By these characters it is to 
be distinguished from both the preceding forms.  Foslie's figures 
