376 W. ARCHER. 



with reddish granules, as equivalent throughout — that is, 

 they could perceive no differentiation into endo- and ectosarc, 

 but there appear to exist a few non-contractile vacuoles. 

 Possibly the coarsely and very densely and opaquely granular 

 substance of the body may render such a characteristic all 

 but impossible to discern. Certain it is that there is a 

 nucleus which I formerly overlooked, which the dense 

 nature of the substance is well calculated to obscure, but 

 it is readily revealed by carmine solution. Greeff was the 

 first to recognise this body. Hertwig and Lesser rightly 

 draw attention to the great delicacy of the pseudopodia, their 

 granuleless nature and their seeming fewness; yet this form, 

 an\ongst Heliozoa, is one of the most vigorous as regards 

 powers of locomotion ; one can often readily enough see it 

 roll along with no very little celerity for such an organism. 



The authors describe a biscuit- shaped constriction of the 

 body-mass. In one case they saw two bodies united by a 

 narrow isthmus of sarcode, each possessing its nucleus. 



Greeff has described an encysted state of this species in 

 which a porous siliceous coat is formed around the inner body. 

 This must be similar to what I have myself observed in the 

 caseoi Spharastrum conglobatum, Greeff := Heterophrys Fockii, 

 niihi (see above). ^ 



H. exigua, Hertwig et Lesser,^ as mentioned, seems to be 

 mainly distinguished from P. punicea, Archer, by its greater 

 minuteness (?), the greater delicacy of the " skeleton," the 

 component spherules of which are more minute and superim- 

 posed in more numerous layers ; it mostly contained one pre- 

 eminently large, ruby-red pigment granule ; a nucleus, with 

 nucleolus, present ; very delicate, homogejieous pseudopodia. 

 As far as is requisite this form has already been referred to 

 under Astrodisculus (ante). It might seemingly be looked 

 upon as a merely diminutive form of H. pu7iicea (?). 



I postpone till next number the consideration of further 

 lately described new rhizopodous forms. 



' ' Marburger Sitzuugsbericlite,' June, 1871. 

 2 Hertwig and Lesser, op. cit., p. 222, t. iv, p. 6. 



