GENUS PACHYTROCHA. 729 



mentioned may be accepted, as in the case of P. furcifer, as representing the 

 intersecting peripheral elements of the ordinary Vorticellidan ciliary wreath, and 

 which are f->r the most part alone distinctly visible during energetic action. 

 From the tine of Leeuwenhoek, who in the year 1675 first described a bell-ani- 

 malcule or Vorticella as possessing two little anteriorly developed horns,* similar 

 horn-like or setose appendages have been ascribed to various members of the same 

 family group. This misinterpretation, while excusable to the early investigators 

 labouring with simple lenses of their own manufacture, is however scarcely expected 

 of an F.R.M.S. of the nineteenth century, working, as Mr. Davies admits, with a 

 T^-inch objective, and having the accumulated experiences of two centuries to fall 

 back upon. 



Pyxicola socialis has been recently reported by Mereschkowsky \ from the 

 Solowetz Islands, in the White Sea. 



Pyxicola Carter!, S. K. PL. XL. FIG. 40. 



Lorica elongate subcylindrical, three times as long as broad, rounded 

 and attached posteriorly by a very short or rudimentary pedicle, constricted 

 at a little distance below the even, slightly oblique, anterior margin, the 

 side walls more or less irregularly undulate ; animalcule attenuate, project- 

 ing when extended to a considerable distance beyond the orifice of the 

 lorica ; the operculum borne on the infero-lateral surface of a conspicuous 

 conical protuberance that projects from beneath the peristome-border ; 

 colour of lorica and operculum yellow or dark brown according to age, 

 animalcule transparent. Dimensions unrecorded. 



HAB. Fresh water : Bombay (H. J. C.) ; Victoria Regia House, 

 Botanic Gardens, Regent's Park (S. K.). 



The above name was first conferred upon an infusorial form included in some MS. 

 notes upon the Infusoria of Bombay, kindly placed at the author's disposal by Mr. 

 Carter, and which has been since personally obtained developed in great abundance 

 on Conferva and other water-plants growing in the comparatively hot water of the 

 Victoria Regia House in the Regent's Park Botanic Gardens. The irregular undula- 

 tion of the walls of the lorica readily distinguishes it from all of the species previously 

 enumerated. In his original drawing, Mr. Carter has represented the anal aperture 

 as debouching at the apex of the conical projection which supports the operculum ; 

 but in this particular the author anticipates there has been some misconception, 

 so essential a deviation from the typical histological formula being scarcely probable. 



GENUS XVI. PACHYTROCHA, S. K. 

 (Greek, pachus, thick ; troches, wheel.) 



Animalcules loricate, corresponding in all points with those of Pyxicola, 

 with the exception that a fleshy pad is developed in place of the indurated 

 operculum distinctive of that genus. 



Pachytrocha cothurnoides, S. K. PL. XL. FIG. 32. 



Lorica transparent, urceolate, somewhat gibbous, widest and inflated 

 posteriorly, the anterior aperture somewhat obliquely set, about twice as 

 long as broad, mounted on a pedicle which rarely equals one-quarter of its 



* See Vol. I. pp. 4 and 8. t 'Annals of Natural History,' March 1881. 



