62 



BUITISH FRESHWATER EHIZOPODA. 



variety differing only from the type in its smaller size 

 occurs, and may be distinguished as A r . vitrsea var. 

 minor as suggested by Penard ; it is about 140 /a to 

 150 /A in length ; it has not yet been recorded from the 

 British Isles and is rare in Switzerland, but at Lake- 

 hurst in New Jersey it is the dominant type. 



1. Quadrulella symmetrica var. irregularis Penard. 

 (Fig. 173.) 



QvadruUa symmetrica var. irregularis 



PENARD in Amer. Natur. XXV (1891). p. 1073; Faune Eliiz. Leman 



(1902), p. 378; Proc. R. Soc. Ediiib. XXV, 8 (1905), pp. 595, 597. 

 CASH Brit. Freshw. Rhiz. II (1909), p. 132. 

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



p. 142. pi. vi, f. 31. 

 WAILES in Jrn. Linn. Soc., Zool. XXXII (1912), p. 142, pi. xii, f. 20. 



FIG. 173. Quadrulella symmetrica var. irregularis. x 250. 



Test larger than in the type, moderately com- 

 pressed, the fundus, in broad side view, hemispherical 

 with the sides tapering in nearly straight lines to the 

 aperture ; the aperture devoid of lips and without 

 any constriction of the neck ; plasma and pseudopodia 

 as in the type. 



Length 130 p to 160 /x; breadth 55/u, to 60 /x; 

 aperture in greatest width 23 p to 30 p. 



