126 
SUPPLEMENT. 
shows a central axial-cell surrounded by several primary radiating cells, and many 
external rows of secondary cells which become smaller towards the circumference. 
Colour a dull brownish red. Substance cartilaginous, not adhering to paper. 
I have seen but a single specimen of this seemingly very distinct plant, which has 
more the habit of Champia lumbricalis than of one of the present genus. It was picked 
up, it is presumed on the Western coast, by Dr. Schott, during the Mexican Boundary 
Survey, but no note regarding its exact habitat accompanied the specimen. I am 
indebted to my friend Professor Torrey for specimens of this and other Algae collected 
by the officers attached to the Mexican Boundary Survey. 
Plate L. B. — Fig. 1. Chondria nidifica ; the natural size. Fig. 2. Portion of a 
branch, with a tuft of ramuli. Fig. 3, a ramulus, containing tetraspores. Fig. 4, a tetra- 
spore. Fig. 5, transverse section of a branch ; the latter figures more or less magnified. 
Page 26, add, 
4.* Khodomela lycopodioides, Ag. ; frond divided near the base into several long, 
simple branches, which are densely beset with slender, finely divided branchlets, mixed 
with the short, rigid, bristlelike remains of a former series. Ag. Sp. Alg. 1 . p. 377- 
Harv. Fhyc. Brit. t. 50. Lophura lycopodioides , Kutz. Sp. Alg. p. 850. Fucus lyco- 
podioides , Linn. Turn. Hist. t. 12. E. Bot. t. 1163. 
Hab. Whalefish Islands, Davis Straits, Dr. Lyall. (v. s.) 
Fronds 1-2 feet long, half a line in diameter at base, attenuated upwards, filiform, 
either quite simple or divided a short way above the root into several long simple 
branches. In its winter state the virgate branches are closely set with short, rigid, 
simple or slight divided ramuli, from half an inch to one inch in length. In summer, long ? 
capillary, multifid ramuli from one to two inches in length are thrown out both from 
the remains of the winter ramuli and from the main branches, and the frond thus 
acquires a plumose aspect very different from its winter state. ’ Conceptacles are abun- 
dantly borne on the summer ramuli ; and tetraspores , lodged in clustered, podlike 
branchlets or stichidia, are found on the winter ramuli. Substance cartilaginous. 
Colour a purplish brown, becoming very dark in drying. 
This interesting addition to the American Nereis occurs abundantly in various places 
on the shores of Northern Europe. In the British Isles it is almost confined to the 
coasts of Scotland and of the North of Ireland ; but has occassonally been met with on 
the East coast of England. 
Page 59, 
1. Dasya Gibbesii, Harv. 
Add to the description : Conceptacles of large size (A> inch in diameter), borne on 
the penultimate ramuli, at first globose, afterwards broadly ovate, inflated, with thin ? 
highly cellular walls and a berry-like nucleus of much branched filaments, bearing many 
