BE. W. BERGER ON THE CUBOMEDUS. 35 
in a jar of about twenty centimeters in diameter. It came to the 
surface every now and then, after eight to fifteen pulsations. The 
tentacles and the phacelli were of a lilac shade. If a pencil was 
placed in its way it would pulsate against it repeatedly without any 
effort to dodge around it. 
6.58 A. M., 124 pulsations were counted to the minute. 
8.00 “ 124 t ‘ é i f 
9.25 “ 136 ‘ : ‘ t 
1045) 18 é z : 
11.00 “ 146 ; ‘ i i 
At 10.15 it went around the dish in eight seconds, taking eighteen 
or nineteen pulsations. If a bright platinum spatula or a black 
pencil was placed in its circuit it would repeatedly butt against 
it each time it came around. After the second or third pulsation 
against it, however, it seemed to have some sense to change its 
direction. 
b. The pedalia have no perceptible action of their own. They 
move inwards slightly toward the axis at each pulsation, but 
scarcely as much as one would suppose from their attachment to 
the pulsating margin. It seems as if they were for “winging” the 
moving animal more than for anything else. 
c. The velarium is loose and it flaps. It seems to take part in 
swimming something more than the passive diaphragm function,— 
i.e., it straightens out during the recovery after each contraction of 
the bell. 
AURELIA AND POLYCLONIA. 
[The following experiments were performed at Port Henderson, 
Jamaica, in 1896.] 
42. May 12th. An Aurelia was pulsating normally at the rate 
of twenty-five or twenty-six pulsations to the half-minute. One 
lithocyst was cut out, when a few contractions, evidently caused by 
the stimulus of cutting, followed; then, rest. In the first minute 
there were only about five pulsations. In two or three minutes 
rhythmic pulsations were resumed. Four minutes after the cutting 
there were nineteen pulsations to the half-minute. About twenty 
minutes after there were nine to the half-minute, in groups of six 
and three. 
