NUCLEARIA. 109 
Genus 18. NUCLEARIA Cienkowski, 1865. 
ee Cienkowskr in Arch. f. mikr. Anat. I (1865), 
p. 225. 
Heterophrys Arcugr in Q. J. micr. Sci. X, n.s. (1870), p. 110. 
Heliophrys (pars) Greere in Arch, f. Mikr. Anat. XI 
(1875), p. 28. 
Single- or multiple-nucleated amoeboid organisms, 
with or without a mucous envelope, which, when 
present, is defined by a granulated surface and an 
irregular outer margin, often villous in appearance, 
from the presence of innumerable delicate radiating 
processes or spicules imbedded in the mucus. The 
body, in its initial form sub-spherical, emitting a variable 
number of sharply-pointed radiating or irregularly- 
disposed pseudopodia; during activity varying in 
contour from sub-spherical to quadrate or roughly 
triangular, the angles not infrequently acute and pro- 
duced into elongated tapering sharply-pointed straight 
or branched pseudopodia; the mucous envelope when 
present adapting itself to the mutations of the animal. 
This genus is allied to Vampyrella. Certain species 
(e.g. WV. delicatula) when resting, simulate the Heliozoa, 
as does V. lateritia in some of its phases; but their 
habit of assuming amoeboid forms, and their usually 
straight and sharply-pointed pseudopodia, distinguish 
the Nuclearix. 
1. Nuclearia delicatula Cienkowski. 
(Plate XIT.) 
Nuclearia delicatula Crenxowssr in Arch. f. mikr, Anat. I 
(1865), p. 225, t. xiv, ff. 74-78; Birscuur in Bronn’s 
Thier-Reichs, I, 6 (1880), t. xiii, f. 1; Maaer in Rend. R. 
Ist. Lomb. (2) XIII (1880), pp. 729, 732; Biocumany 
Mikr. Thierw. Siisswass. (1886), p. 20, t. ii, f. 43, and ed. 2 
(1895), p. 21, t. ii, f. 32; Carranzo in Boll. Scient. III, 
an. 10 (1888), p. 94; Saccur in Boll. Scient. ITI, an. 10 
(1888), p. 48; Anrarz in Zool. Anzeig. XII (1889), p. 409, 
ff. 1-12; Casu in Trans. Manch. Micr. Soc. 1891 (1892), 
p. 52; Detaae and Hérovarp Zool. concr. I (1896), p. 163, 
f, 244; Frenzen Mikr. Fauna Argent. I, Prot. 4 (1897), 
