E. W. BERGER ON THE CUBOMEDUS^E. 39 



CASSIOPEIA. 



[The remaining experiments were all performed in 1897, at Port 

 Antonio.] 



49. Removal of the sixteen marginal bodies caused paralysis for 

 a time ; then recovery followed. 



Contraction was limited to the subumbrella. 



A portion of the subumbrella not from the margin can contract 

 by itself as well as a portion of the margin with the marginal bodies 

 (lithocysts). 



In the margin cut off as a strip with only one marginal body 

 attached at one end, contractions sometimes started from the opposite 

 end. 



AURELIA. 



50. Size, seventeen or eighteen millimeters. Pulsations, thirty-two. 

 Lithocysts, nine. The operation consisted in the removal of the 

 concretions with as little injury to the pigmented parts of the 

 marginal bodies as possible. One whole marginal body, however, was 

 removed in the operation. Soon after the operation the pulsations 

 were 28, 26, 20, 20, per minute. 



Another one; size fifteen millimeters. Pulsations were forty per 

 minute. The operation consisted in the removal of the concretions 

 and pigmented parts of the marginal bodies with as little injury to 

 the adjoining parts as possible. After the operation it seemed as if 

 the intervals between the pulsations were irregular, not a series at 

 regular intervals. An hour or so after the operation the pulsations 

 were very intermittent. During the afternoon it was not seen to 

 pulsate except when it was stirred up, when six or seven vigorous 

 pulsations followed. These, however, were rather aimless. 



51. One sensory club (marginal body) was cut out, including its 

 basal part also. In one or two other cases more or less injury was 

 done to adjoining parts also. Pulsations ceased upon the removal of 

 the last club, but upon placing it in an aquarium and allowing it to 

 come to rest for two or three minutes, pulsations were now and then 

 seen. In the evening, this one and another did not pulsate except 

 when stirred, when they pulsated with good progress. 



52. A circular cut, about two inches in diameter, was made 

 through the epithelium of the subumbrella around the base of the 



