ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
71 
absence of skeleton and in being polynuclear it agrees with Actino- 
sphaerium, but the plasma is not vacuolated, and there is a definite centre 
from which the axial filaments radiate. The diameter does not exceed 
•14 mm. Three layers — medullary, cortical, and enveloping — are 
described. Fission and conjugation (binary and multiple) were 
observed. 
A New Vorticella.* — Dr. F. Romer describes Vorticella vaga sp. n., 
an unstalked species. Its internal structure is like that of other species, 
and the external characteristics are only slightly divergent. It is pear- 
shaped or bell-shaped, with a posterior ring of cilia in a shallow groove, 
with the usual adoral spiral, with horseshoe-shaped macronucleus, and 
two contractile vacuoles which empty themselves about once every 
minute. Longitudinal division was observed, and encystation, but no 
conjugation. 
Parasites of Cyclopidse.f — Dr. W. Schewiakoff describes Tokophrya 
cyclopum Cl. and L., one of the Acinetae, an ectoparasite of Cyclops and 
Gammarus pulex, and Trichoplirya cordiformis sp. n., on Cyclops phalera- 
tus ; and gives diagnoses of the four known species of Trichophrya. In 
many freshwater Cyclopidas certain endoparasitic Sporozoa are common, 
occurring in amoeboid, encysted, and spore-forming states. That these 
are Myxosporidia the author doubts, nor does he find that they corre- 
spond with the forms which Henneguy and Thelohan have described as 
Thelohania g. n., but what they are he does not decide. 
Polymorphism of Peridinium acuminatum.^ — M. G. Pouchet shows 
chiefly by a figure the extraordinary polymorphism of this species. At 
least eight distinct types can be recognized, and of these at least three 
should, in the present mode of systematically classifying Peridinese, be 
placed in another genus. 
Classification of Sporozoa.§ — Sig. Mingazzini proposes the following 
new classification : — 
Rounded or ovate, immobile, not 
conjugating, living in cells and 
tissues. 
V ariable in form, mobile, generally 
Iree. If conjugation obtains it is 
almost always by apposition. 
'Body formed of two segments, of 
which the anterior is cephaloid ; 
sometimes there is, anteriorly, an 
accessory segment. If conjugation 
obtain, it is almost always by 
apposition. 
Body formed of three segments, of 
which the anterior is cephaloid. 
The individual results from the 
conjugation of two by apposition. 
* Biol. Centralbl., xiii. (1893) pp. 464-7 (2 figs.). 
t Bull. Soc. Imp. Nat., 1893, pp. 1-29 (1 pi.). 
X Comptes Rendus, cxvii. (1893) pp. 703-5 (1 fig.). 
§ Ricerche Lab. Anat. Norm. Univ. Roma. See Biol. Centralbl., xiii. (1893) 
p. 632. 
Body formed by ( 
one segment 
Body formed of 
two or several 
segments 
Coccididea . . 
Monocystidea 
Polycystidea 
Didymophidea 
p 
