8 Art. 3.— K. Yatsn: 



spönded. Yery seldom three or four pedälia were ]jent by the 

 pinching at one place. As the upper edge of such preparation is 

 below the sensory niches, the main nerve connections between the 

 rhopalia and pedalia have of course l)een severed. How pinching 

 stimuli are transmitted in this region, I could not make out, es- 

 pecially in view of the fact deduced from the experiments already 

 mentioned, that the nerve plexus do not seem to be present in 

 the immediate neighborhood of the velarium. 



IV. Oral arm reaction. 



Various parts of the medusa were stimulated to see how the 

 oral arms respond. Only when the sul)uml)rella close to the 

 velarium was stroked, the oral arms performed a peculiar groping 

 movement without " pointing." Neither the touching of the oral 

 arms nor of the inner surface of the stomach produced any effect 

 at all. In C. xaijmacana, it may bo noted, the removal of one or 

 all rhopalia induced a strange movement of the oral arms (Berger 

 '00 p. 11). In the Japane^se form the oral a.rms do not respond 

 to such a stimulus. 



V. Phacellae. 



The phacellae of C. rastonil was described l)y Bigelow ('09 pp. 

 17 and 18) from preserved specimens as follows : " the filaments 

 of each phacella have become 

 collected into three or four groups, 

 each group arising from a distinct 

 stalk. The filaments, furthermore, 

 arise from the stalk at different 

 levels and some of them are ap- 

 parently branched, so that they pig. 4. 



