NUCLEARIA. 109 



G-enus 13. NUCLEARIA Cienkowski, 1865. 



Nuclearia CIENKOWSKI in Arch. f. mikr. Anat. I (1865), 



p. 225. 



Heterophrys ARCHER in Q. J. micr. Sci. X, n.s. (1870), p. 110. 

 Heliophrys (pars) GREEFF 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. N. 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 Nuclearise. 



1. Nuclearia delicatula Cienkowski. 



(Plate XII.). 



Nuclearia delicatula CIENKOWSKI in Arch. f. mikr. Anat. I 

 (1865), p. 225, t. xiv, ff. 74-78; BUTSCHLI in Bronn's 

 Thier-Reichs, I, 6 (1880), t. xiii, f. 1 ; MAGGI in Rend. R. 

 1st, Lomh. (2) XIII (1880), pp. 729, 732; BLOCHMANN 

 Mikr. Thierw. Susswass. (1886), p. 20, t. ii, f. 43, and ed. 2 

 (1895), p. 21, t. ii, f. 32 ; CATTANEO in Boll. Scient, III, 

 an. 10 (1888), p. 94 ; SACCHI in Boll. Scient. Ill, an. 10 

 (1888), p. 43; ARTARI in Zool. Anzeig. XII (1889), p. 409, 

 ff. 1-12; CASH in Trans. Manch. Micr. Soc. 1891 (1892), 

 p. 52 ; DELAGE and HEROUARD Zool. concr. I (1896), p. 163, 

 f. 244; FRENZEL Mikr. Fauna Argent. I, Prot. 4 (1897), 



