1 . B. triloculare Hemprich & Ehrenberg; syn. B. articulatum Ehrenberg. 
2. B. enchelys Ehrenberg; sp. inquirencla. 
3. B. punctum Ehrenberg; sp. inquirenda; syns. Fionas punctum Muller?; Mela- 
nella monadina Bory, 1824; Bacterium punctum Ehrenberg; Bacterium ? punctum 
Ehrenberg, and Dujardin. 
4. Bacterium termo (Muller) Dujardin; sp. inquirenda; syn. Monas termo Muller. 
Cohn (1872, 168) in his emended Bacterium cites two species, 
namely: B. termo Ehrenberg, 1830, Dujardin, 1811; and B. lineola 
(Muller). As neither of these species was among* the original species 
of the genus (1828), and as Ehrenberg himself, as author of the genus, 
cited (1832a, 59) “ B.f termo ” with reserve, it will be seen that Cohn 
has used the genus in a sense not altogether in harmony with its first 
publication (namely, he eliminated the type of the genus). 
Migula (1897, 1) states that Bacterium triloculare , B. enchelys , and 
B. ymnctum of Ehrenberg are no longer recognizable. As diagnosis 
of the genus he (1900, 280) gives the following: 
Kiirze oder lange cylindrische Zellen, zuweilen Faden von nicht unbetracht- 
licher Lange bildend, ohne Geisseln. Endosporenbildung ist bei vielen Arten be- 
kannt, bei anderen scheint sie vollkonunen zu fehlen, bei vielen jeaoch diirften sie 
noch bei passenden Bedingungen nachzuweisen sein. 
It will be thus seen that Bacterium Ehrenberg as used by Migula 
is not in harmony with Ehrenberg’s description of his type, namely, a 
fiagellated form. 
If bacteriologists continue to use Bacterium in the sense used by 
Migula, the question does not concern the zoologists and does not 
come under the zoological code. Our duty with the genus ceases with 
the date that Bacterium was eliminated from zoology. The zoolog- 
ical code provides, however, that the generic name preserves its 
nomenclatural status and that we can not use Bacterium for any other 
later genus or supposed genus in zoology. Should the time come that 
Bacterium is transferred again to the protozoa, it should, according 
to the zoological code, be judged upon the basis of its type, Bacterium 
triloculare. 
Species BACTERIUM ARTICULATUM Kern, 1897 . 
Migula gives Bacterium articulatum Kern, 1897, as a valid species 
of Bacterium , but attention may be called to the fact that Ehrenberg, 
1832c, 69, reports a Bacterium articulatum. Kern’s species can not 
retain this name unless it is claimed that it is identical with Ehrenberg’s 
form, in which case it should be attributed to Ehrenberg. Ehrenberg 
(1838a) cites B. articulatum Ehrenberg as a synonym of B. triloculare 
Hemprich & Ehrenberg. 
