148 MR. G. H. WAILES ON FRESHWATER RHIZOPODA 



some localities. These tests, when empty, are characterised by the peculiar 

 optical effect of the small circles formed by the imbrication of the scales at 

 their upper and lower edges ; in living individuals the outlines of the scales 

 are obscured from view by the plasma. 



The form of the spines is subject to the same variation as in E. armata : 

 they may be either (a) short and truncate, (b) short and pointed, (c) long and 

 straight, or (d) long and flexuous ; they are sometimes incurved. Tests 

 destitute of spines are occasionally found. 



Leidy, pi. 35. fig. 2, shows an individual 160 /j, in length (none were seen 

 by me over 140 /^), but it may represent a double-sized encystment test. 



Var. MINOR, var. no v. (PI. 12. fig. 38.) 



Test similar to type, but smaller and usually destitute of spines. 



Length 80-110 /u- ; breadth 45-Gl /x ; aperture 16-20 /ll. 



Habitat. Lakes and ponds. 



Distribution. Split Rock Lake, N.J., and Long Island, N.Y. 



Is usually glabrous, but when provided with spines only distinguished 

 from jE. armata by the shape of the body-scales. 



The body-scales are somewhat different in shape from those of the type ; 

 they are shown in fig. 38. When incorporated in the tests of Nebela collaris 

 and N. eqidcalceus they are displayed with ])erfect distinctness, and can be 

 observed even better than when artifi-cially isolated. These scales are 

 generally 11-12 // in length, but the width varies according to the position 

 they occupy on the test, those centrally placed being the widest. 



EUGLYPHA FILIFERA, Pen. (34). 



U. ciliata pars, Leidy, pi- tj6. figs. 7, 11-14 ; pi. 37. fiji'. :?8. 



The test of this species as found in Europe is oviform in shape, and the . 

 spines are distributed at regular intervals in a single row ; the compression 

 of the test is slight, the ratio of the transverse axes not exceeding 4:5. Jn 

 the United States the following forms are found : — 



(a) Test similar to European type (Leidy, pi. 36. fig. 7). 



(&) The spines are duplicated and arranged in a double row or rarely 

 irregularly (Leidy, pi. 36. figs. 11-13). 



(c) The test is constricted near the aperture and is more compressed, the 

 ratio of the transverse axes being 2 : 3 (Leidy, pi. 36. fig. 14). 



{d) The testis of typical form but sparsely covered with scattered s[)ines — 

 var. spinosa, var. nov. 



The forms (a) and (b) occur at Lakehnrst and at Good Ground, L.I. 

 Dimensions : Length 73-93 /jl ; breadth 30-42 fju : aperture 10-15 /a. 

 Transverse section from subcircular to a ratio of axes of 4:5. Spines 

 20-30 /jt, long. 



