14 BRITISH FRESHWATER RHIZOPODA. 



ately to the length, the crown arched and provided 

 ■with two to four short mamillary protuberances, or 

 conical blunt spines, which are not always sym- 

 metrically situated nor of uniform length. Pseudo- 

 podia massive, branching or lobed, and penetrated by 

 the granular endoplasm. Nucleus normal. 



Dimensions : Length (omitting the spines) 300- 

 350 iJi ; breadth 250-300 n. 



In pond at Ohipperfield, Herts, 1904 {A. Earland). 



Examples from the locality above mentioned, gathered 

 in the summer of 1904, were remarkable for the varia- 

 tions they presented no less than for their extraordinary 

 size. In some individuals the diameter of the test was 

 equal to about two-thirds of the length ; others were 

 nearly as broad as long ; and the protuberances, which 

 consisted of an agglomeration of coarse sand-grains, 

 were arranged in a cruciform manner, one on the apex 

 and one on each side of the test at its broadest part, 

 whilst the neck varied, being in some examples shortly 

 cylindrical, in others tapering downwards to the trun- 

 cated mouth. A few examples met with were four- 

 spined. In all cases the test, apart from the spines, was 

 typically pyriform in broad lateral view ; it was, how- 

 ever, more or less compressed in side view, and there- 

 fore, in transverse section, elliptic. In this latter respect 

 it difPers from all other forms of B. oblonga Ehrenb. 



3. Difflugia Penardi nom. nov* 

 (Plate XVIII, figs. 4-6.) 



Diffltu/iaproteiformisEKTiKiiBmiG (pars) ?Infusionsth. (1838), 



p. 131, t. ix, f. 1 d, p. 

 Difflugia globulosa Leidy (pars) Fresliw. Rhiz. N. Amer. 



(1879), p. 96, t. XV, ff. 25, 26. 

 Difflugia fallax Penard (pars) in Mem. Soc. Geneve, XXXI 



(1890), 2, p. 144, t. iv, ff. 41-43 ; m Amer. Nat. XXY 



* [Diffl/uffia fallax Penard: Cash, MS. This name having since the death 

 of Mr. Cash been found to 'le pre-oooupied, that of the first describer of tlie 

 species. Dr. Eugene Penard of Geneva, who has so thoroughly investigated 

 the rhizopodal favina of the Swiss lakes, is substituted for it.] 



