46 CLASS I. 
Family II. Amebea. Animalcules naked, emitting and retract-. 
ing irregular, mutable lobes by continuous motion. 
Ameba Enrens. (Proteus MUELL.) 
Sp. Ameba difluens EnRENB., Volvow Chaos L., Proteus diflwens MUELL. ; 
RogseEL, ns. 111. Tab. ct. fig. a—T ;1 MUELL., Infus. Tab. 11. fig. 1...12; 
ERRENB., Jnfusionsth. Tab. vit. fig. xii. A gelatinous mass, of rounded 
form, if the entire animal contracts itself on disturbance of the water ; 
when the water becomes quite at rest the body extends itself variously 
into lobes and processes, which are drawn in again. RoxESEL observed 
these parts to be even torn asunder by extension, so that there arose two 
animals (Propagation by spontaneous division). The name Proteus had 
been previously given (by LAURENTI) to a genus of Reptiles, and was on 
that account changed into Amiba? by Bory, and into Ameba by EnREN- 
BERG. [Perhaps Ame@ba is a temporary state of other forms, as of the 
shelled Rhizopods, &c. Vid. LIzBERKUEHN, in MUELLER’s Archiv. 1854, 
s. 17, and CoHN in SIEBOLD and KoELLIKER’S, Zeitsch f. Wissenschaft. Zool. 
Bd. tv. s. 262.] 
Family III. Arcedlina. Animalcules enclosed in a membranous 
lorica or calcareous test, partly exsertile from their covering, and 
emitting processes sometimes filiform and branched. 
They are small calcareous forms (shells) divided into cells, found 
in sea-sand and in a fossil state in the Chalk-formation, and espe- 
cially in the coarse tertiary limestone. These miscroscopic crea- 
tures occur in incredible numbers, 6000 of them having been 
counted in an ounce of sand from the Adriatic sea, whilst an 
ounce from the shore of the Antilles contains, by computation, near 
four millions. They were investigated at the end of the last cen- 
tury by Sonpant, and in the present by Ficnren and Mott, and 
afterwards especially by D’Orsicny, who defined more than 1600 
species of them. Until within a few years these bodies were refer- 
red to the Molluscous Division, genus Nautilus L. (Cephalopoda, 
vid. the first edition of this Manual, u. pp. 107, 108). Recent 
observations, however, consign these Polythalamia or Cellulacea to 
a much lower position, near the genus Proteus of Mueller. Although 
D’Orpieny has been satisfied by the investigations of- DusaRDIN 
that these animals do not belong to the Molluscs, he still believes 
that they ought to be considered as a distinct class of the animal 
kingdom (standing between the Polyps and Echinoderms), and 
calls them Foraminifera, the same name under which he formerly 
' Bory DE St Vincent and DusarDIN refer these figures to another species, sup- 
posed to differ from Proteus diffluens by its greater size. 
2 Dictionn. class. d’ Hist. natur. 1. 1822. p. 261. 
