118 



paler colour and more hyaline appearance, its more delicate 

 structure, the apertures indistinct, and perhaps most notably 

 by an evident pulsation of certain of its vacuoles. But such 

 examples seetii not unusually to present themselves where 

 the ordinary highly coloured and most marked examples 

 occur, and I would venture to suppose they are but younger 

 specimens, or examples more than ordinarily retarded. 



Had 1 known the further figures of this species were forth- 

 coming from Greef 's hand, I would not have ventured to 

 put forward the too stiff figure I have given on PI. XVII, 



fig- 5- 



Such will, I believe, convey a true conception of what 



this pretty rhizopod is. Cienkowski designated it as hardly 

 distinguishable from Actinophrys sol within the stipitate 

 shell; but Greef justly points out that it does not exactly 

 bear ont that comjiarison. An Actinophrys presents a truly 

 globular figure, its circular outline not interrupted by the 

 passage off" of the evenly set and regularly distributed pseu- 

 dopodia, and it is marked by the striking marginal pulsat- 

 ing vacuoles. Opposed to this the body of Clathrulina is 

 more mobile, though of a general rather rounded figure; the 

 pseudopodia var)ing in thickness, and some of them, ex- 

 panding at the base, lend a more lobed appearance to the 

 outline. Neither are the pulsating vacuoles by any means 

 so frequent or so striking, if, indeed, they can be strictly at- 

 tributed to this form. These in themselves may appear to 

 many to be very small and trivial distinctions, but such, at 

 first sight, not very striking idiosyncrasies soon attract the 

 notice of observers bestowing a closer attention on these 

 beings, and, as I think, are ere long seen in certain forms to 

 pxit forward a not unfounded claim to be regarded as special 

 and inherent. 



Greef states that he has perceived in young and paler ex- 

 amples that (as in Actinosph(srium Eichhornii, for instance) 

 a differentiated " axile" and " cortical" region in the granu- 

 liferous pseudopodia can be made out, but he has not been 

 able to satisfy himself that an uninterrupted connection exists 

 between the axes and a vesicular " nucleus-like" central 

 bo ly, said by him to be constantly present, which 1 think, 

 however, must be queried just as yet, though such an appa- 

 rent structure no doubt sometimes shows itself, and I imagine 

 it may be what I ventured to suppose in my, from time to 

 time, casual remarks before our Microscopical Club might 

 possibly be the representative of a " central capsule." It is 

 to be remarked that none of GreeFs figures (figs. 1, 6, 7) ac- 

 tually depict either this presumed central " nuclear" body or 



