236 Ameba Proteus. [ April, 
The first notice we have of the discovery of an Ameda, is by 
Rosel, in a work entitled “ Insecten Belustigung,” or Recreation 
among Insects, published in Nurnberg in 1755. Rosel calls the 
animal the little Proteus, and accompanies his description with 
colored figures engraved by himself. 
Linnzus, in the Systema Nature, referring to Rosel’s animal, 
named it Volvox Chaos, and afterwards Chaos Protheus. Nearly at 
‘the same time Pallas called it Volvox Proteus. Müller subsequently 
gave it the name of Volvox Sphaerula, but later, after having him- 
self observed the animal, described and figured it under the name 
Proteus diffiuens. 
As the generic name of Proteus had been previously appropri- 
ated for the well known salamandroid of Adelsberg, Bory de St. 
Vincent substituted that of Amba for the animal of Rösel and 
Miller, calling it by the various names of Amiba divergens, A. 
` Röseli and A. Mülleri. : 
In 1830, Ehrenberg described a comparatively small Amæba, 
which together with all others previously noticed by different au- 
thors, he referred to the same species under the name of Amada 
diffiuens. In 1831, in the Transactions of the Academy of Sciences, 
of Berlin, p. 79, Ehrenberg described what he considered to be a 
new species of Ameéa with the name of A. princeps. Its charac- 
ters are as follows: “ diameter 1-6th of a line; body transparent, 
yellowish, with many readily and voluntarily movable blunt pro- 
cesses, four times larger than the Proteus.” In 1838, in his great 
work, the Infusionsthierchen, Ehrenberg described Amba prin- 
ceps as “large, yellowish, equaling 1-6th of a line, provided with 
a variable number of cylindrical appendages, thick and. rounded 
at the end.” 
Accompanying the former description there is also O 
Ameba diffluens as follows: “diameter 1-24th of a line, body 
clear as water, with mostly three or four variable processes; four 
times less than the former species.” In the Infusionsthierchen 
the same is described as “ branching, rarely extending or exceed- 
ing 1-24th of a line, colorless, with processes variable, moderately 
long, robust, and subacute.” 
From the descriptions it appears to me that Rösel’s little 
ne of 
Proteus 
accords with Ehrenberg’s Amba princeps, and not with Ameba . 
diffluens. Ehrenberg says A.‘princeps is four times larger than the 3 
Proteus, meaning A. diffluens, and not the Proteus of Rosel, for 
