Sketch of the Infusoria of the family Be oe me 
' Its endochrome usually presents a central mass, from which 
several (10?) undulating ‘ils radiate to the carapace. It is a 
very elegant species. 
5. Closterium lineatum. (Fig.34? Pl1.) Very long, acute, slightly 
arcuate, cylindrical, filiform in the middle, the ends trunca te, and very 
acute, (‘‘ trés amincis,”) ridges distinct, in form of smooth Teal Often 
thirty times longer than broad, +5 to 4 of a line. 
Compare with this fig. 34, Pl. 1, which represents a species 
quite common in ponds near ‘West Point, and which also occurs 
in Virginia. The figure represents only one half of the exces- 
sively elongated body. In the living specimens, the endochrome 
shows distinct ridges. 
6. Closterium striolatum. (Fig, 35? PI. 1.) Fusiform and arcuate, 
ends acute and truncate, ridges smooth, not deep, ten or twelve times 
longer than broad, +1, line. 
Compare fig. 35, Pl. 1, which represents a common species. 
7. Closterium rostratum, Ehr. Fusiform, slender, ends acute, seta- 
ceous horns about as long. as the body, sormatines. shorter. _ C. acus, 
Kitz. Linn., 1833, fig. 81. 
I suspect the species shown in fig. 36, Pl. EE is a young state 
of this species. I found it among Lemna minor, on Staten Isl- 
and, New York. Fig. 36, a, shows an individual produced by 
Spontaneous division, one portion of which is still imperfectly de- 
velo 
ed. , 
8. bet tenue, Kiz. ‘*Corpusculis minutis lineari-lanceolatis, 
viridi hyalinis, transverse fasciatis acutis.” See Linnea, 1833, Pl. 8, 
fig. 78. 
_I find no notice of this species in the extract from Ehrenberg’s 
work, appended to Mandl’s work on the microscope, but as Kuet- 
zing’s fig. 78 resembles our species, (fig. 37, Pl. 1,) 1 quote his 
description, that they may be compared. 
Our species occurs in vast abundance on the muddy bottom of 
abrook which crosses the Canterbury road, a few miles from 
West Point. It forms a mass of such extent, and of so bright 
& green color, that I at first mistook it for a layer of Oscillatoria. 
‘There are very fine transverse lines, often visible on the cara- 
Pace, and it often appears as if a portion of the shell between 
these lines (as at a, b, fig. 37, Pl. 1) had been removed. Its mo- 
tions are distinct and lively. 
9. Closterium (Fig. 38, Pl. 1.) Nearly cylindrical, con- 
tracted in the middle, ends obtuse, and in one position showing a re- 
