Jan., 1905.] 



Adinolophus minutus. 



261 



ACTINOLOPHUS MINUTUS A NEW HELIOZOAN, WITH A 

 REVIEW OF THE SPECIES ENUMERATED IN 



THE GENUS.* 



L. B. Walton. 



While examining late in October some sediment in a jar con- 

 taining Hydra jusca collected September 17, 1904, in the Koko- 

 sing River, attention was attracted by a small stalked form of 

 heliozoan like appearance. This (Fig. 1), a single example of 



which was observed, on more careful 

 j,»d. study proved referable to the genus 

 --■c.u(i) Actinolophus (Heliozoa) the representa- 

 ■je. fives of which are not met with fre- 

 n. quently, none to the knowledge of the 

 present writer having thus far been noted 

 in America. 



Although there is considerable uncer- 

 tainty as to the exact relation of the spe- 

 cies constituting the group to the other 

 Protozoa, the characteristics of the form 

 in question appear to merit record, dif- 

 fering as it does from A . capiiatus Penard 

 through the absence of knobbed pseu- 

 dopodia as well as in its much smaller 

 size, and from A. pedatus (Zach.) by the 

 spherical form of the body which is ovoid 

 in the latter and much larger than the 

 body of A. minutus. 



Schulze, 1874, formed the genus 

 Actinolophus for the reception of A. 

 pedunculatus a marine form from the 

 Baltic Sea described by him. Penard 

 1890, described A. capitatits from a single 

 individual suggesting its close relation- 

 ship with the tentacliferous infusoria 

 (Suctoria). Zacharias, 1893, in a brief 

 description, called attention to a new 

 Heliozoan, Actinosphceridimn pedatus 

 which Schaudinn, 1896, in his monograph 

 of the Heliozoa, placed provisionally in 

 the genus Actinolophus, recognizing for 

 that genus three species, two of which were of doubtful value. Pen- 

 ard, 1904, in his valuable monograph of the fresh water Heliozoa, 

 mentions both A. capitatus and A. pedatus among forms whose 

 position is doubtful, suggesting possible affinities with Tokophrya 

 and Nuclearia, noting at the same time the desirability for further 



* Read before the Ohio State Academy of Science. Nov. 26, 1904. 



Fig. 1. Actinolophus minutus 

 n. sp. (x 1000), psd. — pseudopo- 

 dia, c. V. — contractile vesicle ( ?), 

 p. — pedicle, g. e. — gelatinous 

 envelope, n. — nucleus. 



