109 



not be at all disposed to regard it as a young state of A. 

 turfacea; the very smallest examples I have ever seen of the 

 latter have shown the radiating spine-like spicules, and I 

 have seen examples smaller than the average of those of H. 

 Fockii. In this form I have not been able to see anything 

 to represent a " nucleus" or a " central capsule." I have in 

 a previous j)art of this paper expressed my own dissent from 

 the view that the outer boundary of the inner globe in such 

 a form as this can be rightly looked upon as the representa- 

 tive of the " central capsule." It has sometimes suggested 

 itself to me that this form might be identical with that 

 figured by Carter^i which he provisionally considered might be 

 a young condition of Actinosphcerimn Eichhornii, but whether 

 I may be right or wrong in that conjecture, I conceive the 

 structure of H. Fockii to be quite unlike even a young state 

 of ActinosphcBrium Eichhornii, nor have I been able to see 

 any nucleus as shown by Carter. 



I perceive that Leuckart," in giving the favour of a notice 

 to my communication to the Dublin Microscopical Club, in 

 which I first chronicled this rhizopod, suggestively puts it 

 that it may appertain to Greef's genus Amphizonella, esta- 

 blished by him in a previous paper ,3 but this is most clearly 

 not so. JNIy form is not at all referable to Amphizonella ; 

 in that genus the Amoeba- or Difflugia-like, riucleus-b earing 

 sarcode body is surrounded by a resistent so-called " cap- 

 sule," still yielding enough to permit the exit of a few 

 finger-like pseudopodia. Thus, that genus would difier from 

 Heterophrys sufficiently widely to fall under a completely 

 distinct group of Rhizopoda, no matter which of the hitherto 

 proposed schemes of classification one might lean to adopt. 

 There is doubtless somewhat more resemblance in Greef's 

 new genus Astrodisculus to his previously established 

 Amphizonella, to which, indeed, he himself refers ; but still 

 even they apj^ear abundantly distinct, and I quite concur, so 

 far as I may venture to express an opinion, that the forms 

 respectively referable to Amphizonella and Astrodisculus 

 demand being placed wide apart. I shall endeavour below 

 briefly to recapitulate the characteristics as given by Greef 

 in his recent paper of this latter new genus. 



J ' Anuals of Natural History,' vol. xiii (lS6i), pi. ii, fi^^^ 23. 



* 'Bericht iiber die wissenscliaftliclie Leistungeii in der Naturgeschicte 

 der niederen TLiere,' 1S6G, 1S67, p. 270. 



* Greet", " Ueber ciiiige in der Erde lebende Amcfibeu uud andere Rhizo- 

 poden," in Scliultze's ' Archiv fur mikroskopische Anatoniie/ 1866, p. 323, 

 et seqq., t. xviii. 



