ROTATORIA 



163 



C. wiszniewskii n. n. Length 1S)0 (type), 100-140/x (Weber), toe 21/^, about one-ninth of the 

 total length, short, wide basally, anterior margin very slightly concave, widest at the uncon- 

 stricted base. (Figure la.) 



f. volvocicola (Zavadovski). Length 126/*, toe 19/t, about one-seventh of the total length, 

 moderately narrow basally, anterior border strongly concave, widest at the practically uncon- 

 stricted base. (Figure lb.) 



C. clmcntcita de Beauchamp. Length 210/*, toe (from figure) 18/t, short, narrow, strongly 

 curved, the anterior border concave, the posterior convex, basally constricted and widest 

 distinctly distally to base. (Figure 1 e.) 



Figure 1. — E.xternal aspect of left toe of A, C. wiszniewskii n. n. ; B, C. iv. f. volvocicola (Zavadovski) ; 

 C, C. catclUna (Miiller) ; D, C. c. f. ahlstromi n. ; E, C. clmcntcita de Beauchamp, redrawn from 

 de Beauchamp. 



The tropin are essentially similar in all these forms, the characteristic asymmetrical 

 development of a tooth on the distal edge of the right ramus is particularly well marked in 

 South African specimens of f. z'olz'ocicola and in the East African C. litiicntcita. 



2. Filinia loiigiscfa (Ehrenberg) and F. terminalis (Plate). In plankton samples 

 from the lake at Ootacamund two forms of Filinia are not uncommon. One of these is a 

 typical limnetic form of F. longiseta, the other is a form with a small very narrow spindle- 

 shaped body and completely terminal insertion of the posterior seta. No intermediates occur 

 between the two forms in these samples. The form with the terminal insertion of the pos- 

 terior seta was met with in South Africa by Hutchinson, Pickford and Schuurman. Some 

 of their material was kindly examined by Mr. D. Bryce, who pointed out that this form is 

 referable to F. terniinalis (Plate), a species which has been rarely found in Europe and 

 which was placed in the synonymy of F. loiigisctahy Harring. Unfortunately Plate (1886) 

 gives no figures but there is no reason to doul)t that Mr. Brycc's determination is correct and 

 as the two forms are frequently found together in South .Africa as well as in the Ootacamund 

 locality, without any intermediate forms occurring, there seems no reason why F. feniiinalis 

 should not be accorded specific rank. The speci;s may be easily recognised by its small narrow 

 spindle-shaped body and by the insertion of the posterior seta ( Figure 2c) as pointed out above. 



It is probable that the chief reason for the almost universal failure to recognise 

 F. tcrmitialis is to be fmuid in the great varialjility of the distance l.)etween the posterior end 



