98 
F. W. PHILLIPS-NOTES ON THE 
of a pear-shaped form, and has a well-developed collar and flagellum, 
which (as in all other members of the family) can be entirely 
withdrawn into the body. Mr. Saville Kent gives in his ‘ Manual’ 
two figures, showing their withdrawal, the monad having changed 
into an amoeboid form. The members of this genus multiply by 
fission, or self-division, and the newly-formed animalcule swims off 
as a simple monad, but, after finding a resting-place, developes in 
due time the characteristic collar. Of this genus I have also found 
M. Steinii, which is of a more even contour, equal at both ex¬ 
tremities, and was found sparingly distributed, on the stem of 
Vorticella campanula: it is named specifically after its discoverer 
Friedrich Stein. Also, M. fusiformis, which is spindle-shaped, 
and sharply pointed at both extremities. Both species, like the 
first, are sessile. M. glohosa is another species of this genus, but 
distinguished from the foregoing by its globular form, and more 
particularly by the possession of a long straight pedicel of great 
delicacy. This species was taken from water collected in the 
hollows formed by the roots of beech-trees in Ware Park. If 
searched for with a high power, it would probably be overlooked, 
as the length of its pedicel places the body at some distance from 
the object to which it is attached. 
We now come to the second genus, Codosiga , in which the 
various species are distinguished by being united in social clusters 
by a fixed, rigid, branching pedicel (technically termed a zooden- 
drium). The commonest form is C. hotrytis. Being imperfectly 
observed by Ehrenberg, it was described by him as Epistylis 
hotrytis. It is exceedingly abundant in many ponds. I may 
instance the pond in Mangrove Lane, near Hertford, from which I 
rarely take a dip without finding this beautiful form attached to 
Myriophyllum , and to the ivy-leaved duckweed ( Lemna trisulca ), 
often in such abundance as to present the appearance of a perfect 
forest of vegetation. The animalcules of this species are of a 
symmetrically-ovate form, attached in clusters of from two to twenty 
zooids to the extremity of the various branches of the zoodendrium. 
A peculiar feature in the species is the habit of putting forth 
certain rod-like bodies before undergoing encystment: on a casual 
inspection these appear to be merely particles of adherent mat¬ 
ter. Their distinct connexion with the body was traced by 
Mr. Saville Kent, who at one time considered that the possession 
marked a distinct species, upon which, from its bristling appearance, 
he conferred the title of Codosiga echinoides; but a subsequent and 
prolonged examination showed him that these rod-like bodies were 
pseudopodic projections. Usually, but not always, the collar and 
the flagellum are withdrawn into the body previous to this amoeboid 
phase. Then follows the encystment, the cuticle becomes har¬ 
dened, and the enclosed protoplasm breaks up into a number of 
spores. Stein believes that a genetic conjugation with some other 
free-swimming animalcule precedes this encysting process. Mr. 
Saville Kent records a peculiar phenomenon, which I have also 
observed in connection with the group, viz. that when subjected 
