468 



MEDUSJE OF THE WORLD. 



These 8 main pouches are, however, cleft by the 8 tentacles, thus giving 16 peripheral lobes, 

 and they may be even further subdivided peripherally, so that there may be 32 peripheral out- 

 pocketings of the stomach; peronial loop-canals are usually present. 



Haeckel's genus Cunoctona is separated from JEginura by the fact that there are otoporpae 

 above the marginal clubs in Cunoctona, whereas these are absent in JEginura. This distinction 

 appears to me to be of specific rather than of generic value. JEginura as here defined is closely 

 related to Cunoctantha but is distinguished by the fact that its 8 principal stomach-pouches 

 are cleft by the roots of the 8 tentacles. In Cunoctantha, on the other hand, the insertions of 

 the 8 tentacles lie above the 8 stomach-pouches, the outer margins of which are simple and 

 entire and not cleft by the tentacles. 



Vanhoffen, 1907, 1908, would restrict JEginura to include forms with a marginal canal- 

 system, whereas Cunoctona according to his scheme would embrace medusae having no peronial 

 canal-system. 



Synopsis of Species of JEginura* 



*M. incisa^ Cunoctantha incisa Mayer is an immature form described in the text. 



.SJginura myosura Haeckel. 



JEginura myosura, Haickel, 1879, Syst. der Medusen, p. 343, taf. 19, fign. 8, 9; 1881, Report Deep-sea Medusa;, Challenger 

 Expedition, vol. 4, Zool., p. 41, plates 13, 14, figs. I-I2. — Maas, 1905, Craspedoten Medusen der Sihoga Expedition, 

 Monog. 10, p. 76. 



Bell 30 mm. wide, 15 mm. high, flat top, evenly rounded, bulging sides probably almost 

 hemispherical when alive. The 8 tentacles were not all of the same size. The 4 radial ten- 



