KECENT MEMOIRS ON FRESHWATER RDIZOPODA. 357 



body ofSph. conglobatum consists of a clear homogeneous sub- 

 stance with numerous more or less coarse and fine granules. 

 In the centre lies a comparatively large and clear globular 

 body, with a darker nucleus, more readily coming to view 

 by increased pressure. This form is mostly united into 

 colonies of 10 — 20 individuals, each of which measures about 

 0-03 mm." 



In the foregoing there is no mention made of " skeleton " 

 nor " spicules," but the outer envelope presented itself to 

 the author as " ein breiter heller Sarkodesaum " — so it ap- 

 peared to myself, though doubtless AvhoUy distinct from the 

 body-substance in character and texture. Doubtless the 

 " Gewirr von vielfach verschlungenen Linien " to be seen 

 therein is just what I originally described as that sort of 

 texture which presented a " streaky " appearance. No 

 doubt GreefF's " grosse helle Kugel, mit dunklerem Kern," 

 which I at first overlooked, but which is truly there, is to be 

 regarded simply as nucleus and nucleolus. In my own ex- 

 perience this is not a very uncommon form, but by far more 

 frequently occurs singly than combined into colonies, whilst 

 such composed of 2 — 3 — ^4 individuals occur more frequently 

 than those of 10 — 20 (as described by Greeff), but even so 

 large colonies as the latter no doubt sometimes jjresent them- 

 selves. Touching Greeflf's remarks as to the unequal distri- 

 bution of the pseudopodia, it holds good to the fullest extent 

 only in such as are so grouped together into colonies — single 

 isolated individuals seem to give off the pseudopodia uni- 

 formly all round. Can a former figure of GreefF's^ refer to 

 this form occurring singly, at the time conjecturally thought 

 to be a developmental state of Acanthocystis viridis 9 



Whether this form has been studied by Hertwig and 

 Lesser does not appear. Granting GreefPs view and my own 

 as to the outer region being a mobile soft stratum (probably 

 in young individuals only by degrees becoming, as it were, 

 excreted and deposited externally), and devoid of hard parts 

 (spicules), then surely it forms a strong case in point for 

 the necessity of a group between the naked Askeleta and 

 the undoubted JSkeletophora. Here at any rate we have not 

 the peripheral linear processes, forming in marginal view 

 that fimbriated border to be seen in Heterophrys myriopoda, 

 H. spinifera, Sec, and which are claimed by Hertwig and 

 Lesser as " spines,^' the genus Heterophrys being hence by 

 them relegated to the Skeletophora. We have certainly 

 the outer border running into subtriangular projections, the 

 intervals between which produce those sinuses which cause 

 ' • Schultze's Archiv,' Bd. v, t. xxvii, f. 35. 



