CLASSIFICATION OF THE KLIIZOI'ODS. 7 



Class. RHIZOPODA. 

 Order I. Protoplasta ; II. Heliozoa ; III. Radiolaria ; 



IV. FORAMINIFERA; V. MoNERA. 



The distinguished French naturalist Dujardin, who first recognized the 

 nature of the Rhizopoda, and applied to them this name, included in the 

 class the Foraminifera and the group of Protoplasta, excepting only the 

 genus Amoeba, although he fully understood the relationship of this with 

 the former. The Heliozoa he viewed as another division of the Protozoa, 

 and in his day the Radiolaria were not sufficiently known to hold a recog- 

 nized position in zoological systems. 



Prof. Haeckel, one of the latest and highest authorities on all that 

 concerns the lowest forms of life, includes in the class the Foraminifera, 

 the Heliozoa, and the Radiolaria. The Protoplasta and the Monera, which 

 names originated with him, he regards as two distinct and additional classes 

 in his proposed kingdom of Protista (protiston, primordial). 



Prof. Carpenter includes all the ordinal groups above indicated as 

 Rhizopoda, but associates the Heliozoa in the order of Radiolaria. 



Dr. Wallich* divides the class into three orders: the Hc-rpnemata, the 

 Protodermata, and the Proteina. In the first are included the Gromida, 

 Foraminifera, and Polycystina ; in the second, the Thalassicollidse and 

 Acanthometrina ; and in the third, or highest order, the Actinophryna, 

 Lagynidae, and Amcebina. 



Prof. Huxley drops the name of Rhizopoda altogether, and distributes 

 the groups into two divisions of the Protozoa : the Monera and the Endo- 

 plastica To the former he refers the Monera of Haeckel and the Fora- 

 minifera ; to the latter he refers the Radiolaria, including the Heliozoa, the 

 Protoplasta, the Gregarinidae, the Catallacta, and the Infusoria. The essen- 

 tial character of the Monei'a, according to Haeckel, the founder of the order, 

 is the absence of a nucleus, but this has recently been shown by Hertwig 

 and Schulze to exist in the Foraminifera. Carter, Greeff, and others, speak 

 of the Heliozoa as fresh-water Radiolaria. Hertwig and Lesser, who gave 

 the name of Heliozoa to the ordinal group, regard them as of a distinct class 

 from the Radiolaria, and, excluding these, they associate the former together 



* Annals anil Magazine of Natural History, 186IJ, xi, p. 438. 



