GENUS VORTICELLA. 68 1 



Vorticella dilatata, From. Pl. XLIX. Fig. 19. 



Body broadly campanulate, truncate and widely expanded anteriorly, 

 its breadth equalling the total length, no constriction behind the 

 peristome-border, the posterior extremity narrowly truncate ; oral fossa 

 large ; pharyngeal cleft produced almost through the length of the body ; 

 ciliate throughout, vestibular seta conspicuous ; pedicle short, compara- 

 tively slender; parenchyma white, granular; cuticular surface smooth. 

 Length 1-350". Hab. — Fresh water. 



Although of small size, this species would seem, from De Fromentel's illustration 

 and brief description, to correspond closely with one of the many aspects assumed 

 by Vorticella campanula. As in the case of so many other forms described by him 

 as new, no details, however, are given of the comparative length of the pedicle, of 

 its social or soUtary habits, or other data that would assist in its future identification. 



Vorticella fasciculata, Miill. Pl, XLIX. Fig, 20. 



Body broadly campanulate, the anterior margin reflected ; pedicle from 

 three to five or six times the length of the body. 



Hab. — Pond water, on ConfcrvcE; colour green ; social. 



This species, according to Muller, forms green gelatinous masses upon aquatic 

 plants, not only distinctly visible to the unassisted vision, but of considerable extent. 

 The broadly campanulate contour of the body, as indicated in the original figures 

 and description given by Muller, preclude its identification with Vorticella chloro- 

 stigma as suggested by Ehrenberg. The parenchyma would appear to be very clear 

 and homogeneous, as in V. citri?ia, which species, indeed, except for its dark olive- 

 green colour, it would seem to much more nearly resemble. De Fromentel figures as 

 representing this form an animalcule whose body is entirely colourless and mounted 

 on a pedicle of much greater relative length. He makes no reference to the 

 essentially gregarious habits which so prominently distinguish Miiller's type. 



Vorticella communis, From. Pl. XLIX. Fig. 21. 



Body even, conically campanulate, the length equalling or slightly 

 exceeding the greatest breadth ; peristome-border everted ; ciliary disc but 

 little elevated ; parenchyma transparent ; cuticular surface smooth ; pedicle 

 stout, about four times longer than the body. Length 1-800". 



Hab. — Fresh water. 



This minute type is represented by De Fromentel as a very abundant fresh-water 

 form, whose identity with any of the species of the older writers cannot be satisfac- 

 torily established. 



*** Bodies spheroidal. 



Vorticella globularia. Mull. Pl. XLIX. Fig. 22. 



Body spherical ; peristome small, contracted, and not everted ; pedicle 

 slender, six or seven times longer than the body, retracting spirally. 

 Dimensions unrecorded. 



Hab. — Fresh water, social, attached to a species of Cyclops. 



