2 Brannon . — The Structure and Development of 
Norfolk, New Jersey, and appears abundantly in Long 
Island and Vineyard Sounds. The writer has also collected 
fine specimens at Nantucket. Possessed of brilliant lake-red 
colour and delicate texture, it constitutes a notable specimen 
in every representative collection of the New England 
marine flora. 
History. 
The elder Agardh placed this Alga in the genus Delesseria , 
which ‘ then comprehended almost every Alga with a red 
membranaceous leaf-like frond, and also included within its 
limits Plocamium and Stenogramme l It was referred later 
to Nitophyllum , but was found to differ radically in the form 
of conceptacle, shape of frond, and position of midrib. For 
a time it seemed that it was to have fellowship with Hemineura y 
but the different position of conceptacle, lack of similarity in 
nervation and ramification, gave sufficient distinction to deny 
admission to this genus. 
After a somewhat careful study of the plant, Dr. Harvey 
raised it to the rank of an independent genus. He named it 
Grinnellia , as a memorial to the ‘noble conduct of Henry 
Grinnell of New York, chief promoter of the search after the 
missing Arctic expedition of Sir John Franklin.’ 
General Morphology. 
In his description of Grinnellia , Harvey says that this Alga 
has a frond which is ‘ rosy-red, leaf-like, delicately membra- 
naceous, areolated, symmetrical, traversed by a slender per- 
current midrib. Conceptacles scattered over the surface of 
the membrane, bottle-shaped, with a prominent orifice ; 
placenta basal, somewhat prominent, crowned with a pul- 
vinate tuft of subdichotomous spore-threads whose terminal 
cells are earliest ripened. Spores elliptic oblong or roundish. 
Tetraspores tripartite, immersed in scattered shapeless cellular 
warts. 5 
In addition to these statements regarding the gross anatomy 
