NOTES ON DESMAKESTIA PINNATINERVIA. 171 
We are indebted to Mr. Clarke for the use of his specimen, and 
from it the di'awing has been made. 
Explanation of PulTe XXXI. — E)*ucastru7n FoIUehU^ from the specimen 
collected by Mr. Josliua Clarke. Fig. 1, a flower ; 2, a petal ; 3, the stamen 
and pistil ; 4, the pistil j 5, ripe fruit ; 6, seed ; 7, the embryo ; 8, transrerse 
section of a seed. 
t. 
NOTES ON BESMARESTIA PINNATINERVIA, Montagne. 
By J. E. Gray, F.R.S., EX.S. 
r 
I have lately received from the coast of Cornwall a specimen of an 
olive seaweed that was found growing from the root of a specimen of 
Desmarestia ligidata, near the Lizard. It is, without doubt, the Alga 
figured and described hoxa an imperfect specimen received from Port 
San Sebastian, in Spain, by M, Montagne (Ann. Sc, Nat. ser. 2, 
vol, xviii. t. 7, f- 2), under the name of Desmarestia pinnatinervia ; 
and very probably the same as the Desmarestia Dresnayi, described 
and figured by M. Lamouroux (Diet. d'Hist. Nat. v. 438), from a 
sj^ecimen obtained on the coast of France, and is certainly the same 
as the Desmarestia Dresnayi, var. simplex, described by Crouan, in his 
Alg. Mar. Pinisterie, No. 95. 
: Dr. Harvey, in the Appendix to his * Synopsis of British Algae/ 
p. 206, mentions Desmarestia Dresnayiy Lamouroux, as a new British 
species, "if it is not merely a broad variety of D, ligulata,*^ In the 
appendix to Mrs. Gatty's ' British Seaweeds,' (which is a re-issue of 
the reduced copies of Dr. Harvey's figure, made by Mr. Eeeve to 
illustrate the ' Synopsis,' and published in the Atlas of that work, with a 
new text by Mrs.Gsitty), Desmarestia Dresnayi is introduced as a British 
species^ and the habitat given is Molville Bay, Co. Donegal, 1853, Mr.- 
William Sawers ; it is added, " specimen in Trinity College herbarium, 
Dublin, 10 inches long by 2 wide, but Sawers describes others as 18 inches 
long, breadth 3." By Agardh,and also by Dr. Harvey, this plant is con- 
sidered as only an extravagantly wide form of D. Ugnlata; Harvey adds, 
but no one who has not seen intermediate specimens can easily be- 
lieve this. Kiltzing, ' Species Algarum,' regards D. Dresjiayi and D. 
pinnatinervia as distinct species. The younger Agardh, in his * Species, 
Genera et Ordines Fucoidearum/ p. 170^ places D. pitmatinertia as a 
K 2 
