E. W. BERGER ON THE CUBOMEDUS^. 11 



one or all of the clubs was the strange behavior of the proboscis. 

 This would reach from side to side, expanding and contracting its 

 lips as if trying to grasp something. This behavior is very similar to 

 that of the proboscis of Tiaropsis indicans when Romanes stimulated 

 any part of its subumbrella, or of Limnocodium sorbii, a little fresh- 

 water medusa, when he stimulated its margin or the region of the 

 radial canals. (Ib., p. 242.) 



I may add that I observed a very similar movement of the 

 proboscis of the Olindiad, before mentioned. When I pulled off pieces 

 of its gonads by means of quick jerks, with a small forceps, it would 

 continually reach toward the injured part of its subumbrella. This 

 medusa is generally quite active with its proboscis and can occasion- 

 ally be seen to reach with it. 



Romanes states in one place that the proboscis is not affected by the 

 excision of the margin. This is evidently not the case in Charybdea, 

 in which excision of the sensory clubs (which really belong to the 

 margin see "Cubomedusse") decidedly stimulated the proboscis to 

 active movements. This, furthermore, points to the marginal bodies 

 as being organs of considerable importance in giving information in 

 the life of Charybdea. In Romanes' Sarsia and other medusae, however, 

 the proboscis did respond to the stimulation of the tentacles and the 

 marginal bodies, as also would the bell respond to a stimulation of 

 the proboscis (manubrium), thus showing a reflex nervous connection 

 between these regions of the bell, similar to that described for 

 Charybdea. 



Velarium and Frenula Experiments 18, 29, 30, 41c. "The power 

 of originating contractions" to use Conant's own words, "evidently 

 resides in the velarium or in ganglion cells of the frenula, just 

 as it does in the proboscis and the floor of the stomach." Isolated 

 pieces of the velarium contracted by themselves as did the whole 

 velarium when all other tissue had been removed. An isolated velarium 

 with the margin and the pedalia attached gave irregular contractions. 

 When the pedalia with the interradial ganglia were removed it still 

 contracted ; and when all the other tissue was cut off contractions 

 continued. 



Cutting the velarium caused the pedalia to be strongly contracted 

 inwards so that the tentacles were brought inside the bell. Cutting 

 away the velarium did not interfere with the pulsations of the bell, 

 but progress was much retarded. 



