NOTE ON A THECATED ROTIFER. 



317 



NOTE ON A THECATED KOTIEER FROM 

 SUTTON PARK. 



The last number of tlie " Midland Naturalist " contained a 

 description of the rare Eotifer (Ecistes pilula, which I first exhibited at 

 a meetincr of the Birmingham Natural History and Microscopical Society 

 on the 11th of June last. The same pool in Sutton Park, whence I 

 obtained that species, has since yielded a thecated Eotifer of large size 

 and singular beauty, apparently not yet described, unless indeed it be 

 identical with one recently shown by Mr. Oxley at a meeting of the 

 Koyal Microscopical Society, of which Mr. T. Bolton exhibited a drawing 

 at the June meeting of the Birmingham Society. In the absence of all 

 measurements it is difficult to decide whether these two animals 

 represent the same species, but the diameter of the trochus m Mr. 

 Oxley's drawing appears gi-eater than it is in my specimens and the 

 latter clearly show two tentacular processes, while his figures show only 

 one, though this may result merely from the position m which the animal 

 was sketched. But as both my observations and dx-amngs were made 

 before I had heard of that gentleman's, I beg leave to append a brief 

 description, together with figures drawn under the microscope to an 

 accurate scale, premising that, as I have only found two induiduals, such 

 description is necessarily imperfect, and that I hope next season to be 

 able to renew my observations. 



If the species has not yet received a name, I would suggest that, 

 from the length of its slender foot-stalk, it may be appropriately 

 christened (Ecistes longipes. 



I also give figures of (Ecistes pihda, drawn to the same scale. 

 (Ecistes longipes.-Total length of animal when fuUy extended- 

 •Oloin • when retracted, -O'iein. ; diameter of trochus, -Olim. ; height of 

 theca '-OSoin.; greatest diameter of theca, •029in. Theca semi- 

 transparent, milky-white when viewed by dark back-ground illumination. 

 Ciha of the circular trochus conspicuous, those of the cingulum clearly 

 visible under .a lin. objective. Mastax occupying more than half the 

 diameter of the neck. Tentacular processes two, apparently without 

 terminal setae. 



Ova carried after emission at base of foot-stalk. Foot-stalk corru- 

 gated, especially when retracted. 



(Ecistes pilula.— Dimensions of an average specimen :— Total length of 

 animal when fully extended •025in. ; longer diameter of trochus, -OOSin. ; 

 shorter diameter, -003; height of theca, -OlSin. ; greatest diameter of 



theca, -OOTin. 



A. W. Wills. 



Desceiption op Figures.— Plate V. 

 Figs. 1 and 2.— (Ecistes lovgipes. 



Fi2S. 3 and \.— (Ecistes pilula. 







