l5Y G. 1. FLAY FAIR. 637 



CONCHULIXA. 

 Arcellina. 



Genus Akcella Ehr. 

 Arcklla vulgaris Ehr. 



Cash, Brit. Fru . Rhiz,, i., PI. xv., gives two entirely different 

 forms for the type (figs.l and 14). The latter, with the turned- 

 up base, is the one given by Penard, Faune Rhiz., p. 398; and I 

 have, therefore, considered it to be Ehrenberg's type In the 

 arrangement of a maze of polymorphic forms such as we have in 

 the Rhizopoda, the only hope of producing any order is that 

 every distinct form, which retains its characteristics in many 

 localities, shall have a distinct name. This rule, I have endea- 

 voured to follow out here. A. vulgaris is extremely rare in my 

 gatherings; in ten years, I have seen only three specimens. 



Diam. 137-UO, alt. 60-63; orif. 30-38, alt. 23/u. 



Lismore. 



Arcella kotundata, nom.nov. (PI. xxxiv., f.l). 



Test with a depressed dome in side-view, expanded at the sides 

 above the base-line. No basal angles, the margin of the dome 

 merging into the base in a single, broadly rounded curve. ►Syn., 

 A. vufyaris Cash, pa7'ti')n, I.e., PI. xv., f. 1-3. 



Diam. 47-54, alt. 25-30; orif. 17, alt. 8-9//. 



Lismore (197) Pachmond R.; Wyrallah. 



Var. ALTA, n.var. (PI. xxxiv., f.2). 

 Test with a high, arched dome, everywhere evenly rounded 

 Diam. 33-53, alt. 22-32; orif. 10-15, alt. 4-9/i. 

 Botany (152); Lismore (337;. 



Var. SCROBICULATA, n.var. (PL xxxiv., f.3). 



Test devoid of the usual markings, but covered with coarse, 

 closely set scrobiculations having the appearance of rough 

 granules irregularly disposed. 



Diam. 38-60, alt. 23-35; orif. 12-28, alt. 8-9/x. 



Lismore (197, 263, 292, 307, 327, 328); Wyrallah (310). 



I have never observed this scrobiculation in any except this 

 rounded form. The markings do not show at the edge in 



