98 The Microscope. 



A. Surface smooth (B). 



A. Surface striate or otherwise ornamented (C). 



B. Body conical or elongate (f). 



B. Body broadly campanulate (ft). 



B. Body spheroidal (ftt)- 



C. Body conical or elongate (*). 

 C. Body broadly campanulate (**). 



f. Body three times, or more, as long as wide (§). 



f. Body twice, or less than three times, as long as wide (§g). 



f. Body once and one-half, or less than twice, as long as wide (\\\). 

 If. Width of frontal border exceeding length of body {%). 



ff. Width of frontal border equal to or less than length of body (XX). 



Iff. Pedicle 6 to 7 times as long as the body (a), 



ftt- Pedicle 2 to 3 times as long as the body (b). 



*. Body transversely striate only (e). 



*. Body with an external, cuticular investment (f ). 



**. With an external cellular investment V. veslita, Stokes. 



*# # With transverse striae only (p). 



**. With solid or nucleated bead-like cuticular elevations (r). 



g. Conical-campanulate ; ciliary disc not elevated; peristome ob- 



lique; pedicle 4 to 5 times as long as the body 



V. nebulifera, Ehr. 

 g. Conical elongate ; ciliary disc elevated, cushion like ; peristome 



not oblique. (Pedicle not recorded) V. cucullus, Duj. 



\\. Body conical or conical-campanulate (^[). 

 \\. Body ovate (TO- 

 \\\. Campanulate; peristome border undulate,uneven ; pedicle thick, 



less than twice as long as the body. V. dubia, From. 



\\\. Ovate; pedicle 3 to 4 times as long as the body, inserted into a 

 depression in the posterior extremity. — V.fluvialis, From. 

 Hh Ovate; pedicle 3 to 4 times as long as the body ; no posterior in- 

 dentation, but with an annular line around the posterior 



third. Social V. alba, From. 



1[. Conical-campanulate; pedicle 4 to 5 times as long as the body, 



enclosing minute, linear, scarlet corpuscles. V. picta, Ehr. 



I". Conical ; transparent. In stagnant marsh-water. (Insufficiently 



characterized.) V. gracilis, Duj. 



H". Conical : pedicle 10 to 12 times as long as the body 



V. longiftlum, S. K. 

 1f. Conical; with 2 transverse furrows, behind each of which the 

 body abruptly narrows, and over which it contracts tele- 



scopically. V. telescopica, S. K. 



flfl. Pedicle decumbent, }{ as long as the body, contracting to % a 

 single spiral turn. . V. brevistyla, D'Udek. 



