337 : 
May, 1887, I found the woodwork of the wharves covered with 
a coating of algze, which when examined under the microscope 
consisted of a bewildering confusion of forms; all of which, 
however, could be placed under the known species of our coast 
except one, which I venture to identify as above, on the faith 
of the description and figure in Hauck, Deutschlands Meeres- 
algen, fig. 193, and a specimen from the Adriatic, which I 
owe to Dr. Hauck. The plant is characterised by the rather 
thin cell wall, the cells rather shorter than their diameter, which 
is .OI-.o14 mm., and by the more or less distinct chlorophyll 
ring in each cell. The color is a yellowish green. I have since 
found the same species growing near high water mark, on 
rocky shores at Marblehead and Nahant. 
Halothrix lumbricalis (Kiitz.) Reinke. I first found this 
plant at Cohasset, Mass., in May, 1885 ; it grew in company 
with Castagnea, Punctaria, and other spring algz, on floating 
leaves of Zostera marina. Two or three years later I found it 
similarly at Revere Beach, Mass., and this spring, 1891, I have 
found it at the latter locality, growing luxuriantly and abund- 
antly on the Zostera which grows near low water mark ; it has 
also been found at Bridgeport, Conn., by Mr. Isaac Holden. 
It forms a dense fringe, from 3 mm. to 2 cm. in height, and is 
often hidden from casual observation by other and larger alga 
growing with it. The species was first figured and described by 
Kiitzing as Ectocarpus lumbricalts, the fructification having some 
external resemblance to that of the subgenus Pylatella of Lcto- 
carpus; Hauck transferred it to Elachtsta, which it resembles 
in its unbranched sterile filaments ; Reinke has recently created 
a new genus for it, as a result of his studies of its structure and 
development, which he has published in Algenflora der Westlichen 
Ostsee, Deutsches Antheils, p. 49. He has given very complete 
figures in the Atlas Deutscher Meesesalgen, Tab. I. 
LEctocarpus Mitchelle, Harv. This species was described and 
figured by Harvey in the first part of the Nereis Boreali- Ameri- 
cana, published in 1852. His specimens were collected by Miss 
A. Mitchell of Nantucket, for whom he named it; since that 
time nothing had been heard of it, and the species was beginning 
to be regarded as rather apocryphal. Among some algz recently 
