RECENT MEMOIRS ON FRESHWATER RHIZOPODA. 361 



must most likely be referred to the same genus, as well as 

 the Podo stoma jiligerum, Clap, et Lachm.^ 



The present form resembling, as it does in several points, 

 the Sarcodine described by Hertwig and Lesser as Dactylo- 

 spharium vitreum, might be mistaken therefor. But that 

 form has no flagellum. 



Notwithstanding the mobile character of the body-mass, 

 and (like others of its class) constant changes of contour, 

 still a certain type-form, that is to say, that general figure 

 most frequently recurring and longest retained, was not to 

 be overlooked. 



This might be compared to that of a spindle, at one end 

 more pointed, at the other broadly rounded off, and com- 

 pressed above and below. From the surface of the body — 

 so far as not in contact with the substratum — numerous 

 finger-like pseudopodia proceed. These are about as long 

 as the diameter of the body, usually simple, rarely joined at 

 the base, and with rounded, sometimes conically, attenuated, 

 never filamentary or pointed, extremities. Whilst the posi- 

 tion and direction of the pseudopodopia, sometimes long 

 drawn out and again wholly retracted, are, on the Avhole, 

 variable, still a certain law of arrangement might be noticed, 

 and when once noticed, it readily again strikes the observer. 

 Thus, in the normal figure of the sarcodine, they are but 

 very slightly developed on the "dorsal^' surface, whilst, from 

 the alteral margins as well as from the attenuated anterior 

 extremity they somewhat copiously radiate ; at the posterior 

 end they remain comparatively short, thus the whole gains 

 some of the superficial aspect of some laterally symmetrical 

 creeping animal. 



It is noteworthy that, by reason of the occurrence of the 

 flagellum at a definite position of the body, this being 

 directed straight forward, a differentiation of poles, with a 

 definite principal axis — an anterior and posterior extremity — 

 become expressed. But a definite transverse axis does not 

 seem to exist, still less any real or permanent distinction 

 between " dorsal " and " ventral " surfaces. 



The body consists of a hyaline, strongly refractive, colour- 

 less cortical region, from which the pseudopodia are direct 

 processes, and more thinly-fluid contents, permeated by 

 reddish-yellow globules and colourless granules, the latter 

 as usual, being the seat of digestion. 



The most interesting characteristic of the form is the 

 flagellum. This is about 0*06 — 0*08 mm. long, forming a 



' Clap, et Laclim., ' Etudes sur les Infusoires et les Rhizopodes,' p. 

 441, t. xxi, f. 4—^. 



