OF THE ARCELLINA. 



557 



Genus LECQUEEEUSIA (Schliimberger).— Shell ovo-globular, or retort- 

 shaped, rather depressed, membranous, but resistant ; with a wide short 

 neck, and circular terminal aperture, giving passage to cylindrical thick and 

 obtuse expansions. 



This genus approaches Difflugia (Duj.) in the character of its expansions; 

 but the veiy different form of the shell, and the position of the aperture, 

 sufficiently mark the distinction between the two. Its distinctness is re- 

 garded with doubt by Schultze. 



aquatic plants, in many of the lakes of 

 the Jura chain about Neuchatel. Its 

 diaphanous lorica allows its interior soft 

 hyaline and granular body, strewn with 

 brown specks, to be seen. 



Lecquereusia jurassica. — Shell re- 

 sistant, diaphanous, grey, of a globular 

 figure, but rather depressed, -wdth a short 

 wide neck. Length about 1-250" ; breadth 

 1-315". 



This beautiful species is met with on 



Genus CYPHODERIA (Schlum.). — Lorica membranous, resistant, ovoid, 

 elongated anteriorly, where it is curved and constricted in the form of a 

 neck ; surface marked by prominent points in obHque rows ; aperture circular, 

 oblique ; expansions very long, filiform, very fine at the extremity, and simple 

 or branching. 



The oblique disposition of the rows of points, the obliquity of the aperture, 

 and the character of the expansions, bring this genus into affinity with Tri- 

 nenw (Duj.); but the constriction, forming a neck, seems sufficiently distinc- 

 tive between the two. This genus, though admitted by Eresenius, is treated 

 as doubtful by Schultze. 



Cyphoderia margaritacea. — Lorica i water oftheVosges with vegetable debris. 

 yeUow; the surface is divided into mi- I The form of the lorica varies ; at one time 

 nute facets, which appear like translucent the neck may be but rudimentary ; at 

 points or rows of pearls. Processes attain another the posterior end, instead of 

 twice the length of the shell, and are being wide and rounded, is contracted 

 simple or branched. Length 1-395" ; [ suddenly to a triuicated apex. Aperture 

 breadth 1-840" to 1-408". Common in the i crenidate. 



Genus PSEUDO-DIFELUGIA (Schlum.). — SheU membranous, ovoid or 

 ovo-globular, smooth or striped spirally, with a wide round opening, whence 

 proceed numerous long slender expansions, either simple or branching. 



This genus is allied to Difflugia by the form and character of its shell, but 

 differs from it in the nature of the expansions ; it is admitted as doubtful by 

 Schultze. 



filiform, very long. Length 1-740" to 

 1-465"; breadth 1-890" to 1-740". Found 

 near Mulhouse. 



PsEtrDO-DiFFLUGiA gvaciUs. — Shell 

 bluish brown, brittle ; surface as if beset 

 with minute grains of sand, of a more or 

 less elongated ovoid figure ; expansions 



Genus SPIIEN"ODEPIA (Schlum.). — SheU diaphanous, colourless, resistant, 

 globular, with a flattened wedge-shaped neck ; surface marked by polygonal 

 depressions, disposed in regular oblique rows ; aperture terminal, compressed, 

 almost linear. Expansions filiform, very long and attenuated. 



The form of the aperture and of the neck separates this genus from Trinema 

 and Euglypha, to which it is allied by the structure of its lorica. Schultze 

 treats it as a doubtful genus. 



Sphenoderia /ew^a. — Lorica as above [ slender and simple, or branching. 1-650" 

 described, expansions few, very long, | to 1-520". 



Of all the Rhizopodes I have examined (says Schlumberger), this is the 

 slowest in its movements, and its expansions the most difficult to discover. 

 I have found it on tufts of moss in marshy rivulets. 



