RECENT MEMOIRS ON FRESHWATER RHIZOPODA. Ill 



have a nucleus, and knowing its pseudopodium to be finger- 

 like — that is, " lobose " — we would have before us, as it 

 were, a Difflugia, but with a test not only devoid of any reti- 

 culated marking or special structure, but also without the 

 superposition of any foreign objects (arenaceous particles. &c.). 

 Possibly a *' Difflugian" of such a character would really 

 deserve to be kept apart, as well from such a type as Qua- 

 drula, on the one hand, as from such as (say) Diffiugia 

 pyriformis or D. oblonga on the other ; but in that case it 

 would become a question as to how we should deal with those 

 Difflugian forms with a kind of partially hyaline and cor- 

 rugated or more or less reticulated appearance of the test 

 (not absolutely pellucid, smooth, homogeneous, and " struc- 

 tureless," as in Hyalosphenia) ; such, for instance, as 

 Diffiugia triangulata, Lang (a most marked and decided 

 species); Diffiugia carinata, Archer, &c. ; at any rate, although 

 I have not, 1 believe, seen either form, I should venture ad 

 interim to think the genus Hyalosphenia is justifiable. 



Schulze's new species, too, has a thin, membranous, pel- 

 lucid, and quite structureless chitinoid test ; but it is pyri- 

 form, laterally compressed, at the narrow *' oraF' end abruptly 

 truncate; its length 0*06 mm., greatest breadth 0035 mm., 

 scarcely quarter this breadth at the " mouth," greatest thick- 

 ness 0*015 mm. ; end view (seen from behind) elliptic, with 

 the apices somewhat produced and broadly rounded ; con- 

 tour of mouth (seen from the front) narrow elliptic ; its 

 margin very slightly thickened. The body-mass does not 

 completely fill the test, to which it is united by a number of 

 stolon-like sarcodic processes, as in Quadrula, Pseudochlamys, 

 and others : at the mouth it is in close connection with the 

 test ; the author never perceived, unlike the form described 

 by Stein, any sudden retraction of the body into the interior 

 of the test. The homogeneous clear plasma is pervaded by 

 many pretty nearly equal-sized pale globules or granules; a 

 globular nucleus is posed towards the posterior end, enclosing 

 a few comparatively large dark-looking globular nucleoli, 

 whose number may reach as many as six, or even more. 

 Beside and somewhat in front of the nucleus occur usually 

 two pulsating vacuoles. Any food materials lie in the 

 median region of the body in front of the nucleus. The 

 pseudopodia are finger-like, ordinarily only one, but some- 

 times two or three ; they are permeated by extremely minute 

 granules, of which a movement could be seen, especially in 

 the axial region of the longer pseudopodia. 



