CYPHODERIA TROCHUS. 81 



Length 110-120 /*. 



Habitat. Restricted to deep-water lakes. The 

 type has not been recorded from the British Isles, 

 where the species is represented by two varieties. 



Var. palustris Penard. (PI. XLV, fig. 1, and fig. 

 148 b in text.) 



Cyphoderia trochus 



PENARD (pars) Paune Rhiz. Leraan (1902), p. 488, ff. 1-7. 

 Cyphoderia trochus var. palustris 



WAILES & PENARD in Proc. R. Irish Acad. XXXI, LXV (1911), p. 31, 

 pi. ii, ff. 12, 141 a-c. 



Test more elongate than in the type, the fundus 

 tapering more or less gradually to a pointed apex ; 

 formed of imbricated bi-convex scales ; plasma and 

 pseudopodia as in the type." 



Length 100-125 j*. 



Habitat. Sphagnum. 



Records of G. trochus from the British Isles may 

 refer either to this variety or to G. ampulla var. 

 papillata, these varieties of the two species being very 

 similar in the shape of the tests but distinguishable 

 by the difference in their structure, only the former 

 having imbricated scales. In the absence of definite 

 information on this point, records of G. trochus or its 

 varieties cannot be confirmed. The writer has never 

 found this variety in the British Isles. 



The individual figured by Cash (PI. XLV, fig. 1) 

 apparently represents this variety as the test is of the 

 typical form. 



Var. amphoralis Wailes. (Figs. 148 c, 149, and 150.) 



Cyphoderia ampulla 



PENARD (pars) in Proc. Roy. Soc. Edinb. XXV (1905), p. 602. 

 Cyphoderia ampulla var. imbricata 



PENARD (pars) Sarcodines in Cat. Invert. Suisse (1905), p. 98. 

 BROWN in Naturalist, 1912, p. 181. 

 Cyphoderia trochus var. amphoralis 



WAILES in Proc. R. Irish Acad. XXXI, LXV (1911), pp. 31-32, pi. ii, 

 ff. 13, 14 a-c ; in Jm. Linn. Soc., Zool. XXXII (1912). pp. 126, 128, 

 151 ; in Scott. Natur. 1912, pp. 60, 63. 

 VOL. III. 6 



