Sketch of the Infusoria of the family Badllaria. 303 



Its endochrome usually presents a central mass, from which 

 several (10?) undulating ridges radiate to the carapace. It is a 

 very elegant species. 



5. Closterium lineatum. (Fig. 34 ? PI. 1.) Very long, acute, slightly 

 arcuate, cylindrical, filiform in the middle, the ends truncate, and very 

 acute, (" tres amincis''') ridges distinct, in form of smooth lines. Often 

 thirty times longer than broad, ^^ to -J of a line. 



Compare with this fig. 34, PI. 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 Hving specimens, the endochrome 

 shows distinct ridges. 



6. Closterium striolatum. (Fig. 3.5? PI. 1.) Fusiform and arcuate, 

 ends acute and truncate, ridges smooth, not deep, ten or twelve times 

 longer than broad, yV line. 



Compare fig. 35, PI. 1, which represents a common species. 



7. Closterium rostratum, Ehr. Fusiform, slender, ends acute, seta- 

 ceous horns about as long as the body, sometimes shorter. C. acus, 

 Ktz. Linn., 1833, fig. 81. 



I suspect the species shown in fig. 36, PI. 1, 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- 

 veloped. 



8. Closterium tenue, Ktz. " Corpusculis minutis lineari-lanceolatis, 

 viridi hyalinis, transverse fasciatis acutis." See Linnsea, 1833, PI. 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, PI. 1,) I quote his 

 description, that they may be compared. 



Our species occurs in vast abundance on the muddy bottom of 

 a brook which crosses the Canterbury road, a few miles from 

 West Point. It forms a mass of such extent, and of so bright 

 a 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, 6, fig. 37, PI. 1) had been removed. Its mo- 

 tions are distinct and lively. 



9. Closterium . (Fig. 38, PI. 1.) Nearly cylindrical, con- 

 tracted in the middle, ends obtuse, and in one position showing a re- 



