RECENT MEMOIRS ON FRESHWATER RHIZOPODA. 299 



thocystis turfacea or of Raphidiophrys viridis. Latterly I have 

 not been able to meet with it. I have indeed sometimes sup- 

 posed in the field that I had encountered it, but when I exam- 

 ined the gathering at home what I had really taken has turned 

 out to my disappointment to be Acanthocystis turfacea. 

 Of all freshwater Rhizopoda I think this green Actinophrys 

 appears to me to form the most beautiful object, due as 

 much, if I might so say, to its energetic behaviour as to its 

 fine size, very large pseudopodia, and bright colour : I allude 

 to the very vigorous play of its numerous vacuoles, perpet- 

 ually in action so much so as to impart an everchanging frothy 

 appearance to the whole disc, almost comparable to the carry- 

 ing on of a kind of ebullition. The pseudopodia in this 

 form are extremely long, rather stout, sometimes some of 

 them showing an expansion of a fusiform figure along their 

 length, formed of granular sarcode ; the play of granules 

 up and down very vigorous. Sometimes, though rarely, one 

 could see an inosculation of two or even three of the pseudo- 

 podia ; three starting from the periphery separately might 

 be found joined about halfway along their length and thence 

 continued as a single one to the apex. The periphery of the 

 large contractile vacuoles sometimes showed a pilose appear- 

 ance, being covered all over by a number of closely set 

 delicate hair-like pseudojDodial (?) processes. This form is 

 a rather hungry one, incepting food sometimes of large dimen- 

 sions ; thus one could see it sometimes engulph one of the 

 joints of a neighbouring Mesocarpus (which form rather long 

 objects), gradually embracing it until a firm hold of the joint 

 was attained, when it would naturally break oS" at the suture 

 between it and the adjoining joint, whereupon the captured 

 one would next be seen to be wholly surrounded by the vacu- 

 olar sarcode of the Actinophrys. This form occurred in the 

 county Westmeath and would well deserve a close study, but 

 it seems to be very scarce. I am not at present inclined to 

 consider it as specifically distinct from A. sol, for as is well 

 known the presence of chlorophyll-granules does not appear 

 to be a sufficiently constant character to be accounted as of 

 specific value — thus Amphizonella vestita (Archer, olim), 

 better Cochliopodium vestitum (Archer) (= Cochliopodium 

 pellucidum and C. pilosum, Hertwig and Lesser, which to 

 me appear to be but forms of one and the same species, cf 

 Avhich, however, more hereafter), as well as Acanthocystis 

 turfacea (Carter), and even Raphidiophrys viridis (Archer), 

 all can occur colourless, and I at present am not aware 

 of any further important character, beyond its large size, 

 to separate the fine Actinophrys in question from the 



