to be constructed by me, Raphicliophiys, Heterophrys, 

 Pompholyxophrys, along Avitli the genus Acanthocystis 

 (as well as, possibly (?), Greef's new genus Astrodisculus) , 

 all mutually coincide ; I mean, at least, as it appears to 

 my own observation. I think, then, that in the forms 

 inckided under the genera just named, the body-mass is 

 in all composed of two distinct regions or strata of sar- 

 code, sharply marked off, one within the other, the outer 

 siirroundinf/ the inner as a complete hwestment. These 

 two sarcode regions are distinguished by a sharp line 

 of demarcation, and present considerable difference of ap- 

 pearance, colour, and consistency. The outer region appears 

 to me to be the softer, and more plastic and polymorphous, 

 the inner to be more consistent, and in itself (unacted on by- 

 outward forces) the less changeable in form. When spicula 

 are characteristic of the species, it is the outer region Avliich 

 bears them — Avhen colouring granules (green, red, or yellow) 

 are characteristic of the species, it is the inner region which 

 contains them. It is the inner region which projects the 

 true pseudopodia, these i^assing directly through and through 

 the outer investing region ; and further, it is the inner region 

 which receives and digests the food in such forms as have 

 shown crude objects incepted. But sharply marked off as 

 may be the inner globular portion from the outer investing 

 stratum, there appears no evidence of a " capside " including 

 the former ; nor does it appear, therefore, that the outer can 

 be regarded as homologous with the " extra-capsular," and 

 the inner as corresponding to the " intra-capsular" region of a 

 true or typical Radiolarian. 



It is true that ere now in bringing forward before our 

 Club Heterophrys Fockii for the first time, I have suggested 

 a different view,^ and it is also true that Greef proposed, in 

 his recent paper, the same view Avhich I then suggestively put 

 forward, of the presence in this rhizopod (which I think I see 

 portrayed in his fig. 35), of a "central capsule" represented 

 by the definite outline of the inner globular body. But I do 

 not any longer see the justice of the assumption, when com- 

 pared with the seemingly true ''central capsule" of the forms 

 contained in his new genus Astrodisculus and Acanthocystis 

 spinifera, for the very same sharp line of demarcation exists 

 in those forms ; because they contain within the globular 

 central portion a capsule-like structure, it is unnecessary to 

 assume the outer boundary of the inner region as the repre- 

 sentative of the " central capsule," and yet the globular inner 



1 "Proc. Dub. Micr. Club," 19th Sept. 1867, in ' Quart. Journ. Micr. 

 Science.' 



