APPENDIX 
TO THE CLASS OF INTESTINAL WORMS. 
THERE are certain worms which do not live in other animals, 
but reside in water, or in moist earth, or in vegetable substances 
undergoing acetous fermentation, and which, nevertheless, since in 
form and internal structure they correspond with Ascaris, Oxyuris, 
or Filaria, appear to belong to the order of thread-worms. Some 
of them were by former writers arranged amongst the Infusories, as 
species of the genus Vibrio. To these belong the minute animals 
which Linn aus brought together under the name of Chaos redivi- 
vum, and which were described and figured by MUELLER as varieties 
of one species, Vibrio anguillula (Animalcula infusoria, pp. 63-68), 
although he doubted whether they ought not to be regarded as 
different species of a genus for which he had altready proposed the 
name Anguillula, by naming them Anguillula aceti, Ang. glutinis, 
Ang. fluviatilis, and Ang. marina. The genus Anguillula was 
afterwards adopted by EnRENBERG to distinguish these animals 
from Vibrio!. Dusarpin named the same genus Rhabditis, but 
assigned to it somewhat different characters. 
Anguillula Exrens. (Rhabditis Dus.) Body filiform, pellucid. 
Mouth round, terminal, naked. Anus before the posterior extre- 
mity, sub-terminal. The male with tail naked or amplified by a 
membrane (alate). External genital organ a double spiculum. 
Tail of the female conical, acute. 
Sp. Anguillula aceti GatzE Naturforscher xvut. Tab. m1. figs. 12—18 ; 
DucEs Ann. des Sc. nat. 1X. 1826, Pl. 47, fig. 2; from 1—2 millim, in size ; 
these animals may be frozen without dying, whilst occasionally on the other 
hand a slightly increased temperature affects them mortally. Another 
species, Anguillula glutinis, lives in sour paste (MUELL. Jnfus. Tab. Ix. 
1 Symbole physicee, Phytozoa, and Organisation, systematik und geographisches 
Verhiliniss der Infusionsthierchen, Berlin, 1830, s.68, 105. OKEN in his Lehrb. der 
Naturgesch. 111. 1, 1815, s. 191, places these animals under the genus Gordius, yet 
in the index he keeps Angwillula as the name of a genus, (see s. 847). 
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