4 
twice as long as broad; semi-cell five-lobed, the terminal lobe 
exserted; neck short, dilated, with end somewhat convex; the basal 
and intermediate lobes entire, with a deep obtuse notch between; 
upper margin of the basal lobes nearly horizontal and parallel; no 
prominent scrobicul^, but one large central undulate inflation shown 
in lateral view. End view shows the terminal and intermediate lobes 
notched at each side. Diameter loo//; length about igopt. 
Near Malaga and Manchester, N. J. 
E. PURUM, n. sp. — Small, short; semi-cell 'three-lobed, broader 
than long; basal lobe much inflated, terminal lobe short, dilated and 
notched; in lateral view the base and end are more or less inflated. 
Diameter 35-45^; length 55-70/^. 
The smaller forms from Florida; the larger from Brown's Mills, 
New Jersey. 
This new species is separated from ^5", ^//.f^////;/, Ehrb., by the 
decidedly dilated terminal lobe and more strongly inflated basal lobes. 
E. cuueahm, Jenner.— Harvey Lake, Lycoming Co., Penn., and 
occasionally in New Jersey ponds. 
E. peciinatinn^ Breb. — Semi-cell 3-lobed, terminal lobe dilated, 
usually entire; lateral lobes broad, making the basal portion of the 
semi-cell somewhat quadrilateral, horizontal, and, at each side, emar- 
ginate; lateral view cuneate, with two swellings near the base and 
one at the apex; transverse view oval, with Three lobules on each 
side and one (or imperfectly two) at each end. Diameter 40-50/^; 
length about 75//. 
Minnesota. Although common in England, I obtained this year 
the first specimen found in the United States. A number of varieties 
of this species has been described by specialists in different countries. 
The present is not Ralf's typical form, but a variety. 
Micrasterias apiculata, Menegh. — Harvey Lake, Luzerne Co., 
Penn., and Stillwater, Minn. 
M. SPECIOSA, n. ^/.—Small, somewhat longer than broad, five- 
lobed; lateral lobes unequal, the basal lobes usually with only half 
as many divisions as the intermediate ones; basal lobe bifid, and 
mtermediate lobes twice bifid; the angles of each section drawn 
out mto two spine-like points; terminal lobe rather narrow, linear; 
end exserted and much dilated, usually with three prominent mucros 
at each angle, centre retuse and raised, standing free, with a gap be- 
tween It and the intermediate lobes; a series of small spines often 
to be observed on the margins of the lobes. Diameter of Florida 
form 95^; length iio/^; of New Jersey form, diameter 125-150/^' 
length 155-165//. 
This species is nearly related to M. radiosa, var. omnia, NTord., 
but is smaller; the lobes are not so often and so deeply intersected, 
and the polar lobe is more exserted and has the end more dilated. 
Staurastrum cornutum, n, sp. (Figs. 3 and 4).— Medium size, 
about one-fourth longer than wide, smooth; semi-cell oval or broadly 
elliptic, with a prominent, somewhat mwardly curved aculeus on each 
side; end view triangular, angles rounded, each with a firm spine, 
sides straight or slightly concave. Diameter 55-60//; length about 
70/^. Spines not included in these measurements. 
