100 The Microscope. 



f. Cutieular investment mucilaginous, enclosing scattered, bacteri- 

 form bodies. V. rhabdophora, Stokes. 



g. Peristome % as wide as tbe body-center (j). 



g. Peristome equaling or exceeding the body-center (k). 



h. Peristome narrower than the body-center (i). 



h. Peristome equalling or exceeding the body-center (m). 



i. Body 2 to 3 times as long as wide ; peristome about f as broad as 

 the body-center, with an anterior, nipple-like projection 

 when contracted ; pedicle 3 to 4 times as long as the body. 

 V. putrina, Mull. 



i. Body twice as long as wide; peristome about f as broad as the 

 body-center, without nipple-like projection when contracted; 

 pedicle 3 to 4 times as long as the body. V. utriculus, Stokes. 



j. Fresh-water; pedicle 2 to 6 times as long as the body, which is 

 often sub-spherical V. microstoma, Ehr. 



j. Salt-water ; pedicle twice as long as the ovate body. V. striata, Duj. 



k. Sheath of the pedicle apparently twisted, 7 to 9 times as long as 



the body ; peristome exceeding the body-center 



V. octava, Stokes. 



k. Sheath of the pedicle not twisted ; parenchyma colorless or 

 whitish (1). 



1. Fresh-water; pedicle 10 to 12 times as long as the conical-cam- 

 panulate body V. macroeaulis, Stokes. 



1. Salt-water; pedicle 4 to 5 times as long as the conical-campanu- 



late body V. marina, Greeffe. 



m. Pedicle long, more than 3 times the length of the body (n). 

 m. Pedicle short, less than 3 times the length of the body (o). 



n. Parenchyma green, densely granular ; pedicle 4 to 5 times as long 

 as the body V. chlorostigma, Ehr. 



n. Parenchyma colorless ; body 2 to 3 times as long as wide ; mus- 

 cular thread finely granulate V. elongata, From. 



n. Parenchyma whitish or hyaline; pedicle 3 to 6 times as long as 

 the body. Stagnant water and infusions. V convailaria, L. 



o. Pedicle usually less than twice as long as the obliquely set, color- 

 less body. V. hamata, Ehr. 



o. Pedicle stout, 2 to 3 times as long as the colorless, erect, conical 



body ; peristome slightly wider than the body-center 



V. macrophya, Stokes. 



o. Pedicle short, or 2 to 3 times as long as the brownish, erect, con- 

 ical body ; peristome much wider than the body-center. 

 V. spectabilis, S. K. 



o. Pedicle 1} times as long as the body, which is subcylindrical, 3£ 

 times as long as wide, with 2 anterior and 2 posterior pro- 

 jecting angles V. quadrangularis, S. K. 



