GENUS VORTICELLA. 677 



point of junction with the body, gradually tapering from thence towards 

 its proximal extremity, its external surface conspicuously wrinkled, the 

 central muscular fibrilla produced only through the distal moiety of its 

 total length, simply flexed and not coiled spirally when retracted ; 

 cuticular surface smooth ; parenchyma transparent ; endoplast elongate, 

 band-like. Length 1-600". 



HAB. Pond water, on Asellus aquaticus, social. 



This minute species was obtained by the author attached in small colonies to 

 the above-named crustacean taken from a pond near Ashby-de-la-Zouch, Leicester- 

 shire, in January 1880. A like deportment of the pedicle during contraction as 

 manifested by its simple flexure in place of spiral convolution is shared by the 

 Vorticella brevistyla of D'Udekem, already described, while a similar development 

 of the central muscle-like cord within the distal moiety only of this structure 

 frequently recurs in V. spectabilis. 



Vorticella cucullus, From. PL. XLIX. FIG. 9. 



Body elongate-conical, attenuate, nearly three times as long as broad, 

 widest and slightly everted anteriorly, tapering gradually towards the 

 posterior extremity, the ciliary disc raised cushion-wise above the border 

 of the peristome; surface smooth; pedicle slender, relative proportions 

 unrecorded. Length of body 1-265". HAB. Fresh water. 



Vorticella longifilum, S. K. 

 PL. XXXIV. FIG. 30, AND PL. XLIX. FIG. 10. 



Body conical, attenuate, about twice as long as broad, surface smooth ; 

 peristome slightly dilated ; pedicle exceedingly long and slender, contract- 

 ing spirally, ten or twelve times as long as the body. Length of body 

 1-370". HAB. Fresh water, solitary. 



This species in some respects resembles the Vorticella cucullus of De Fromentel 

 last described, but the body is less attenuate, while the pedicle excepting only the 

 form mentioned below exceeds in length and tenuity that of any species previously 

 described. The few specimens observed were obtained in October 1872, in pond 

 water containing Myriophyllum and other water-plants, from the neighbourhood of 

 Stoke Newington, London. An Egyptian species closely allied to and possibly 

 identical with this type, distinguished by the possession of an equally attenuate 

 pedicle, is described and figured by Schmarda,* under the title of Vorticella macro- 

 styla. The body is, however, apparently evenly ovate, and the peristome-border 

 contracted, but the figure given is on too small a scale for an exact apprehension 

 of its more minute specific characteristics. 



Vorticella telescopica, S. K. 

 PL. XXXIV. FIGS. 31 AND 32, AND PL. XLIX. FIG. n. 



Body conical or elongate-pyriform, tapering towards the posterior 

 extremity, a little over twice as long as broad ; cuticular surface smooth, 

 interrupted posteriorly by two transverse sulci, behind each of which it 

 becomes successively abruptly narrower ; when contracted the wider portions 



* ' Denkschrift der Kaiser. Akacl. der Wiss. Wien,' 1854. 



