103 



presents such a perplexing resemblance to a Diplophrys, pseu- 

 (lopodia drawn in, and the body surrounded by an aggrega- 

 tion of small diatom frustules, fragments, and miscellaneous 

 splinters. I need not, however, further advert to this little 

 organism here, as in the place alluded to I have recorded the 

 little I have ever been able to make out about it. Had I not 

 overlooked it, I Avould have given a figure of this queer little 

 thing on my previous plates — perhaps I may take a future 

 opportunity of doing so. 



I hope 1 may not be thought to have made a too wide and 

 unnecessary digression from the affinities and differences of 

 my Acanthocystis Pertyana, but in contrasting it with Greef's 

 A. spinifera, the remainder became unavoidable. I need 

 hardly say I await with interest Greef's further communi- 

 cation hereupon. 



Genus, Raphidiophrys (Arch.). 



Generic characters. — Rhizopod composed of two distinct 

 sarcode regions — the imier forming one or several rounded 

 individualised definitely bounded hyaline sarcode masses, each 

 containing a subperipheral stratum of colouring granules — 

 the outer more or less coloured, soft, and mobile, bearing nu- 

 merous elongate irregularly scattered siliceous spicula, acute 

 at both ends, and forming a common investment to the inner 

 globular masses, which latter give off long slendef non-coalesc- 

 ing pseudopodia. 



The main distinction of this genus from Acanthocystis is 

 the spicula being solid, no difference in the extremities and 

 scattered every way. The absence of a central capsule 

 excludes it from marine Radiolaria to which it otherwise 

 possesses affinity. 



Raphidiophrys viridis (Arch.) . 

 PL XVI, fig. 2. 



Specific characters. — Inner rounded masses hyaline, globular, 

 loith numerous large chlorophyll granules, arranged in a 

 hollow globular manner ivithin the periphery ; outer region 

 slightly buff-coloured, containing densely numerous elongate 

 very slender more or less curved, acicular spicula, acutely 

 pointed at each end and lying in every possible direction ; pseu- 

 dopodia numerous, extremely slender, very long, hyaline, com- 

 paratively rigid, never coalescing. No evident nucleus nor 

 pulsating vacuoles. 



