ON SHEPHEARDELLA, A NEW TYPE OF MARINE RHIZOPODA. 135 
the body. The chief food of the animal appears to consist of 
Infusoria, which are not as a rule conveyed into the body, 
but digested among the pseudopodia outside the test. 
Life history. — The phenomena connected with the life 
history and reproduction of this remarkable Rhizopod have 
not yet been fully made out, so that the remarks now 
offered are in some measure provisional, and subject to cor- 
rection at some future time. They may be given chron- 
ologically, beginning with a note made August STth, 
when two Shepheardellce under observation in a cell dis- 
appeared entirely during that day and the following night, 
leaving as their only traces a very great number of Amoebae 
of various forms, some of which are reproduced in PI. 
XV, figs. 16, 17, 18. What had become of the integu- 
ments and coloured granular portion of the sarcode I failed 
to find out. All the Amoebae were quite colourless ; most of 
them possessed a nucleus, or more than one, and a contrac- 
tile vesicle. They were very active in their movements for 
from four to six weeks, increasing considerably in size 
during the earlier portion of the period ; but towards the end 
of that time their movements became slower and more 
feeble, and finally ceased altogether, when they collapsed 
into motionless specks of very finely granulated sarcode (PI. 
XV, fig. 19), ultimately becoming so indistinct as to be quite 
unrecognisable amongst the organic debris with which the 
cell had got somewhat obscured. 
Another point noticed was that if some of the sarcode 
from the extended pseudopodia of a Shephear della was taken 
up on the point of a camel-hair pencil, and broken up into 
a number of particles in a drop of sea water on a glass slide, 
each separate particle presently put out long filamentous 
quivering pseudopodia ; and if pseudopodia from two such 
particles happened to touch each other they at once coa- 
lesced. After a very short time these characteristic pseudo- 
podia were all retracted, and the particles became quiescent, 
presently resuming active life, not as before, but as Amoebae, 
crawling by lohose prolongations. 
With a view to ascertaining if possible the mode of repro- 
duction, I put two fine Shephear dellce into a cell on December 
9th, and on the 10th, found they were alive and in all respects 
similar to PI. XV, fig. 2. By December 15th, at 7 p.m., one of 
these had assumed the nearly spherical shape of PI. XV, figs. 
9, a, i, but was still encased by its integument. Two and a 
half hours later it had stretched out again, and become in 
form nearly like PI. XV, fig. 6, pseudopodia being put out 
from ten different orifices. The changes of form during the 
VOL. XX. NEW SER. K 
