374 W. ARCHER. 



discloses sometimes more than one in each individual. The 

 two species agree as mentioned in the form of the spicules, 

 but the outer region in R. pallida appears colourless, in 

 R. viridis it appears of a very pale purplish tinge. Taken, 

 then, altogether, I think Schulze is quite justified in regard- 

 ing his form as a distinct species. 



IRaphidioplirys elegans, Hertvvig et Lesser. (Fig. 19.) 



This very interesting species, which 1 myself have taken 

 but on one single occasion, is, indeed, very unlike R. viridis, 

 though doubtless must be relegated to the same genus. It 

 is much more likely to be taken, at first glance, for a colony 

 or group of the form I referred to Heterophrys under the 

 name of H. Fockii,^ which latter, I ventm-e to suppose, is 

 identical with Sph(£rastrum conglohatum, GreefF,^ of which 

 mention has been made above. But the presence of the 

 peculiarly curved spicules will alone distinguish them. These 

 are much more curved, shorter, more bluntly pointed than 

 in R. viridis. When the specimen is some time on a slide, 

 one sees the conical lobe-like extensions of the outer region 

 become more prominently projected, and the little more than 

 semicircularly curved spicules take a very pretty continuous 

 festoon-like arrangement, as it were, mutually interlinked, 

 and stretching from one pseudopodium to another. 



Hertwig and Lesser describe the globular body-mass 

 (which I may say is considerably smaller than in R. viridis) 

 as mostly, though not always, richly laden with chlorophyll- 

 granules ; in their figure only a very few are shown. In my 

 examples there were none present. Almost in the middle of 

 the globular body-mass there is a nucleus (with nucleolus) ; 

 the authoi's say this occurred to them sometimes of a biscuit- 

 shaped figure, but they did not see any subsequent subdivision 

 of it. They saw no contractile vacuoles (just as little as they 

 appear to occur in R. viridis), nor could the authors perceive 

 any marked differentiation into endo- and ectosarc. 



However, from the subperipheral arrangement of the 

 chlorophyll-granules (notably in R. viridis), it is probable 

 such a differentiation exists. In R. elegans the pseudo- 

 podia appear richly granuliferous — in this quite unlike those 

 of R. viridis, in which they occur as delicate lines of great 

 and equal tenuity throughout, perfectly homogeneous and 

 colourless, "silvery" in appearance, and absolutely straight, 

 and of very great length (seemingly several times longer than 

 those of R. elegans). 



' 'Quart. Journ. Micros. Sci.,' n.s., vol. ix, p. 267. 



- 'Scliultzc's Arcliiv fiir Mikrosk. Anat.,' Bel. xi, p. 29, t. ii, f. 2i. 



