102 Sketch of the Infusoria of the family Bacillaria. 
Miller found his specimens abundant on Ulva latissima ; I found 
mine pretty common among Enteromorpha, Polysiphonia, and 
Potamogeton, which grow together in brackish water on the 
flats in the Hudson River, near West Point. ; 
2. Bacillaria? tabellaris. (PI. 2, fig. 36, a, 6.) Smooth, carapace 
linear, narrow, swollen in the middle, dividing into quadrangular plates 
of variable length, ovary lobed and yellow, 3/5 to gy line, (width of 
filament.) Syn. Diatoma flocculosum, Kutz., Linn. 1833, 17, fig. 67. 
Diatoma flocculosum, Greville, in Brit. Flora, Vol. V, 
This species is very common in all parts of the “eye States 
which I have visited. It is easily recognized by its zigzag 
chains, composed of plates (individuals) of various width, which 
have the middle and two outer edges considerably thickened, as 
is shown in the side view, fig. 36, b, 
In fig. 37, a, b, is represented what I believe to be the full 
grown state of the species. It at first view appears very distinct 
from fig. 36; but on examination, we find the same thickening 
of the middie and ends, and similar transverse lines. The two 
varieties or states occur together; both are also found. fossil. 
They are very abundant e ditches and ponds near West Point. 
3. Bacillaria . 2, fig. 38.) This is a marine vies, 
which | found at Stonington, tas and Staten Island, N. Y., a 
to filamentous Alg. [It is distinguished by having on each half of its 
frustules two lines-which commence near the centre and run straight 
and parallel, until they arrive near the extremities, when they suddenly 
become falcate for a short distance, and then resume their original di- 
rections. The curved portions of the lines have some resemblance to 
the upper portion of a pair of tongs. The position of these lines is very 
similar to those on Bacillaria Bonne heaii. (See Schlechtendal’s Lin- 
ai ht ‘Tab. TV, fig. 1.) 
TESSELLA. 
Free, carapace simple, bivalve or multivalve (siliceous) pris- 
matic, compressed in form of plates, forming zigzag polypidoms 
by imperfect spontaneous division of the body, and perfect divi- 
sion of the carapace. The chains have spontaneous motion 
“Fessella catena. (PI. 2, fig. 39?) Carapace lamelliform, often 
broader than ona 4-24 cto series of transverse strie, ngaperes 
in +35 line. | - 
Fig 39 is cmind Seemapaniai ehhh teaait:x tae sail 
viduals adhering to a dried st site Coinage eid Conn. — 
pears to belong to J. catena. — 7 
