202 PROCEEDINGS OF SOCIETIES, 
Structure of Spines of Stomopneustes variolaris, Lamk.—Mr. 
Mackintosh presented transverse sections of the spines of the fore- 
going species. The structure of the spines of the genus Stomo- 
pneustes somewhat resembles that of Colobocentrotus already de- 
scribed in the Proceedings of the Club. Centrally it consists of 
very fine reticular tissue with rounded interspaces ; extending out- 
wards from this to the circumference is a quantity of network with 
irregular polygonal meshes, containing at intervals pillars of solid 
matter very much larger than, but somewhat of the same shape as, 
those in Heterocentrotus (Acrocladia); extending from the 
central reticulation to the first ring of pillars are a number of solid 
radiating bars, like those which extend from centre to circumference 
in Heterocentrotus. 
Heterophrys marina (?), Hertwig et Lesser, eahibited, from 
fresh water ; and on the proposed genus Ouwrameba, Leidy.—Mr. 
Archer showed an example, treated with Beales’ carmine fluid, of a 
rhizopod which was seemingly indistinguishable from Hertwig and 
Lesser’s form above named (‘Schultze’s Archiv fiir mikr. Anatomie,’ 
vol. x, p. 218), which he had just met with in a gathering made at 
Callery Bog. Leaving out of view the chlorophyll granules, 
generally speaking a somewhat inconstant characteristic in rhizo- 
podous forms, there seems not much—except smaller dimensions 
to distinguish this form from H. myriopoda, Archer. Thus there 
can be little doubt but that Acanthocystis turfacea, Carter, occurs 
colourless, and probably in that condition forms Greeff’s Acantho- 
ceystis pallida (‘Schultze’s Archiv fiir mikr. Anatomie,’ Bd. v, 
p- 489, t. xxvii, f. 19). On the other hand, Raphidiophrys viridis, 
Archer, appears to be always green. The present example well 
showed the nucleus, to adopt Hertwig’s interpretation of this body, 
which has strongly imbibed the carminedye. But what Mr. Archer 
especially wished to direct attention to was that the whole of the 
characteristic fimbriated margin had disappeared under the treat- 
ment, showing that these marginal processes forming the fringe-like 
border between the pseudopodia, and through which these latter, 
proceeding from the central body, issued, were not spines (Stacheln) 
but soft substance, some protoplasmic modification. The true spines 
of Acanthocystis Pertyana, Archer, some examples of which oc- 
curred on the same slide, did not so suffer or become altered under 
the self-same treatment. Hertwig and Lesser speak in H. marina 
of the outer region as a ‘“‘skeleton,’’ and the fringe as “spines.” 
Would not that imply that the structure is hard and siliceous (or, 
as might be in other cases, caleareous) ? In H. Fockii, Archer, there 
are no marginal fringe-like (quasi-spines) at all, but only an ir- 
regularly bounded, striated (“ streaky ”’), perhaps varying in density, 
tenacious kind of fabric (“Gefiige,’ Hertwig), disappearing under 
reagents. On the whole, if the form now drawn attention to be 
identical with H. marina, Hertwig, then that, as a species distinct 
from H. myriopoda, would fall to the ground, though @ priori the 
difference of habitat is in favour of their being distinct.—Had time 
permitted, Mr. Archer would have drawn attention to a dyed speci 
