HELIOZOA. 873 



bases, a special axial substance (Fol). In locomotion the ( arms ' were observed by 

 Hertwig to be simultaneously applied to a surface, and to move the body onwards 

 with a jerk. The protoplasm is granular or homogeneous with, in most instances, 

 clear globules of refrangibility identical with its own (Fol). There are no contrac- 

 tile vacuoles. Fol observed near the concave side of the nucleus globules, a few 

 in small individuals, many in large. The globules divided into two groups which 

 came to lie one on each side of the animal. In some instances one .or both these 

 heaps was replaced by a large body with a figure of 8 cavity. Later on, it contained 

 a spirally constricted body which was set free as a multinucleate holotrichous 

 organism, considered by Fol not to be a parasitic Infusorian but a spermatophore, 

 the small globules of other specimens being ova (!). He thinks that the peculiar 

 bodies seen by Hertwig in Acanthometrids are of analogous nature and to be con- 

 sidered as embryoes. R. Hertwig, J. Z. xi. 1877, pp. 325-331; Id. Organismus 

 der Radiolarien, Dk. Jen. Ges. ii. 1880, p. 176; Fol, Mem. Inst. Nat. GeneVois, 

 xv. 1883. 



The Heliozoa are classified as follows : 



1. Aphrothoraca : no skeleton present ; Actinophrys Sol, Actinosphaerium 

 Eichhornii, Actinolophus, Haeckelina ; Lithocolla, Elaeorhanis, Chondropus. 



2. Chlamydophora, with a continuous soft (? gelatinous) skeleton : Heterophrys, 

 Sphaerastrum, Astrodisculus, Astrococcus. 



3. Chalarothoraca: a loose siliceous skeleton: Pompholyxophrys (= Hyalo- 

 lampe), Raphidiophrys, Pinacocystis, Pinaciophora, Acanthocystis. 



4. Desmothoraca : skeleton, a siliceous shell, more or less globular, pierced by 

 apertures ; free Orbulinella, Elaster ; fixed and pedunculate, Clathrulina, Hedrio- 

 cystis. 



Biitschli, Bronn's Klass. und Ordn. des Thierreichs, i. Protozoa, pp. 261-331 ; 

 Archer, Re'sume', Q. J. M. xvi. 1876; xvii. 1877, and Allman, J. L. S. xiii. 1878, 

 pp. 284-305 ; Leidy, ' Freshwater Rhizopoda of N. America,' U. S. Geological 

 Survey of the Territories, xii. 1879, pp. 233-76 (except pp. 253-8). 



Actinosphaerium, Brandt, Inaug. diss., Halle, 1877. Haeckelina, Merejkowski, 

 A. M. A. xvi. 1879, p. 211. Elaeorhanis, Greeff. A. M. A. xi. 1875, P- 2 3- Acan- 

 thocystis, R. Hertwig, J. Z. xi. 1877, p. 331. Acanthocystis Italica, Raphidiophrys 

 arenosa, Gruber, Nova Acta, xlvi. 1884, pp. 507-8. R. socialis, Leidy, A, N. H. 

 (5), xii. 1883, p. 209. Orbulinella, Entz, Naturhistor. Hefte des Nat. Mus. in 

 Buda-Pesth, pt. i, 1877. Elaster, Grimm, A. M. A. viii. 1872, p. 531. 



Axial filaments and movements of Actinosphaerium, Brandt, SB, Ges. Natf. 

 Freunde zu Berlin, 1878, p. 171 ; structure of protoplasm of same, Biitschli, M. J. 

 xi. 1886, pp. 91-2; digestion in same, and Amoeba, Greenwood, Journal of Physi- 

 ology, vii. 1886 ; mode of catching prey, Maupas, A. Z. Expt. ix. 1881, pp. 357-8. 

 Chlorophyl bodies, see note i, p. 868 ante. Nucleus, Gruber, Z. W. Z. xl. 1884, pp. 

 131-4; cf. Id. and Brandt, Biol. Centralblatt. iii. 1883-4; fission of nucleus in 

 Actinosphaerium, R. Hertwig, J. Z. xvii. 1884. 



Fusion of Actinophrys Sol, Gruber, Z. W. Z. xxxviii. 1883, p. 62-8; cf. Cox, 

 Amer. Monthly Micr. Journal, ii. 1882 ; ency station of do., Cienkowski, A. M. A. i. 

 1865, p. 227 ; and fusion, Lieberkuhn, Arch. f. Anat. und Physiol., 1856, pp. 505-7. 

 Reproduction of Actinosphaerium, Brandt, SB. Ges. Natf. Freunde zu Berlin, 1877, 



