262 
The Ohio Naturalist. 
[Vol. V, No. 3, 
study. Until a better knowledge is obtained of their affinities 
however, it seems advisable to consider them under the genus 
Actinolophus. 
The following summarizes our present knowledge of the group 
and indicates the position of A. minutus in respect to the other 
species 
Genus Actinolophus, Schulze. 
1874 Actinolophus, F. E. Schulze, Arch. mikr. Anat. v. 10, p. 892. 
?1893 Actinosphccridiiim, O. Zacharias, Forschungber Plon, v. 1, p. 15. 
1890 Actinolophus, Schaudinn, Das Tierreich, Heliozoa, Berlin. 
Body spherical or oval, provided with a pedicle the length of 
which is usually much greater than the diameter of the bodv. 
Body generally (always?) provided with a gelatinous envelope 
through which the fine pseudopodia are extended. Nucleus 
excentric. contractile vacuole (?). 
The following table will serve to separate the forms: 
A' Pseudopodia not knobbed at the extremity. 
B' Pedicle 3-4 /a in diameter, marine forms, A. pedunculatus 
B" Pedicle not more than 2 /a in diameter, fresh water forms, 
C’ Body ovoid, diameter 18/a, length 23/a, A. pedaUis 
C* Body spherical, diameter 12/a A. minutus 
N Pseudopodia knobbed at extremity diameter 30/a, fresh 
water forms, A. capitatus 
1. A. pedunculatus, Schulze, 1874 .4. p. F. E. Schulze, Arch. mikr. 
Anat., V. 10 p. 392 f. 1-9. 189G Schtiudinn, Das Tierreich, Heliozoa, 
Berlin, p. 11. 
Length of body, up to 30/a, length of pedicle up to 100/a, diam- 
eter of pedicle 3-4/a. 
Marine, Baltic Sea. 
2. A. pedatus, (Zach.) 1893 ActinosphcBridiiini pedatiim, Zacharias, 
Forschungber. Biol. Stat. Plon., v. 1 p. 15, f. 9a, 9b. 189G ? Actinolophus 
pedatus, Schaudinn, Das Tierreich, Heliozoa, Berlin, p. 11. 1904 ? 
Actinosphceridiunt pedatum, (? Nuclearia caidescens), (? Tokophrya), Pen- 
ard, Les Heliozoaires d’eau douce, p. 318. 
Length of body 23/a, diameter 18/a, length of pedicle 11-30/a, 
diameter 1.7/a. Body provided with a thick gelatinous envelope 
from which extends extremely fine and rather short pseudopodia. 
Nucleus oval, situated in the inferior part of the body. Con- 
tractile vesicle not known. Color pale yellow, individuals occa- 
sionally agglomerated by their bodies into colonies. 
Fresh water, Germany. 
Zacharias placed A. pedatus in a new genus Actinosphaeridium 
on the basis that it differed from Actinolophus by possessing, in 
the encysted condition, plates covering the body. Schaudinn 
enumerates it among the doubtful species of Actinolophus, while 
Penard refers it back to Actinosphaeridium, at the same time call- 
ing attention to its remarkable similarity to Nuclearia and to 
Tokophrya. 
