58 CLASS I. 
Cothurnia Enrens. Animal solitary, sessile, with urceolar 
lorica, pedunculate. 
(According to DusaRDIN not sufficiently distinct from the preceding genus.) 
Phalanx II. Body (in the first period of life) pediculated. 
A. Naked. 
Vorticella MUELL. (exclusive of several species). Animal cam- 
panulate, with a flexible pedicle spirally contractile. 
These animals adhere to water-plants, water-insects, small crustacea (Cyclops), 
&e. At a certain period they part from the stem, and then, as freely 
moving forms, are provided with cilia near the posterior extremity by 
means of which they move forward, whilst the coronet of cilia at the edge 
of the opening is entirely retracted. 
a) with simple pedicle. 
Vorticella EHRENB. Sp. Vorticella convallaria L., Vorticella nebulifera 
ExRENB., ROESEL, Jns. 111. Suppl. figs. 2, 4-7, Muntu. Jnfus. Tab. xiv. 
fig. 1, EHRENB. Tab. xxv. fig. 1.—A very similar species occurs in artificial 
infusions, which on contraction exhibits transverse rings, and which 
EHRENBERG distinguishes as Vortic. convallaria. 
b) with branching pedicle. 
Carchesium EXRRENB. Sp. Vorticella polypina L., Murty. Jnfus. Tab. 
XLVI. figs. 7-9; EnRENB. Jnfus. Tab. xxv. fig. 5; polypes & bouquet 
TREMBLEY ; resembles an umbelliferous shrub, of about one line in size, in 
fresh and also in sea-water ; see Bastrr, Natuurk. Uitspanningen 1, Tab. 
iu. fig. 1, C ; SuaBBER, Natuurk. Verlustigingen 1778. Tab. Vv. fig. 2. 
[Zoothamniwm! EHRENB. 
Sp. Zoothamnium arbuscula EHRENB., Infusionsth. Tab, XXIX. fig. 2.] 
[2 The stem of spirally flexible Vorticellines consists of a wall and an internal 
canal containing a thread, or streak, which does not exactly fillit. When a stem or 
branch divides, the structure of the divided parts is not exactly the same in Carchesium 
and Zoothamnium. In Carchesium the canal and streak of a branch have no connexion 
with the corresponding parts of the stem on which it stands. After each fission 
one only of the fission-progeny occupies the apex of the already existing stem, and 
continues to prolong it by secretion of new matter, the canal and the thread suffering 
no breach of continuity. The other individual secretes at first a short portion of stem 
which is quite solid, and is in connexion with the outer wall only of the stem pre- 
viously existing. It is after this commencement that a new canal and a new streak 
begin to be seen. The same occurs at every subsequent division: the individual at 
the apex has the canal and streak of its stem in continuity with the similar parts 
