25 



On Diaschiza vsy tripes. — A New Rotifer. 



By F. R. Dixon-Nuttall, F.R.M.S. 

 {Read January ISth, 1901). 



Plate 2. (Upper portion.) 



Sp. Ch. Body almost cylindrical. Lorica normal Diaschiza- 

 type. 

 Dorsal cleft narrow, straight. Eye cervical. 

 Foot ventral. Toes short, slightly decurved. 



This little rotifer was found in large numbers in a pond in 

 Knowsley Park, Lancashire, in water brought to me by my 

 friend, the Rev. R. Freeman, throughout the autumn of 1900. 

 From this pond more than a hundred species were determined 

 on different occasions, omitting all the Bdelloida. 



Included in the above hundred were Furcularia eva (one 

 example) ; Diglena clastojns, Coelojncs cavia, and Stephmioceros 

 eichoimii in great numbers ; several Pterodina bidentata, Cephalo- 

 siphon limnias, etc. The Diaschizae found in this pond included 

 semiaperta, jyaeta, lacinulata, globata, ramj^higera, and tenuior. 



Viewed laterally the body of Diascki^a ventrijjes is of equal 

 height throughout, but the prone face and slightly concave ventral 

 surface, together with the more convex dorsal outline, give it a, 

 rotund appearance. The posterior extremity does not taper 

 slowly down to the foot, as in D. rcmiphigera, tenuior, etc., but 

 ends in a clear sac-like projection over the base of the foot. 



Viewed dorsally, the outline of the head is semicircular, of a 

 diameter almost equal to that of the body at the neck, from 

 which it is separated by a slight but well-marked constriction. 



