CONTENTS 



HYDROMEDUSAE FROM THE DISCOVERY COLLECTIONS (published 2nd February 

 1957) 

 By P. L. Kramp 



Introduction P^^ 3 



Systematic Account 4 



Anthomedusae 4 



Leptomedusae 27 



Limnomedusae ......••••••••• 4^ 



Trachymedusae 45 



Narcomedusae 63 



Narcomedusae : commensal larvae 89 



ZOOGEOGRAPHICAL REMARKS 93 



Distribution of the species of Hydromedusae taken by the Discovery Investigations . . 94 



Neritic species of Leptolina 9^ 



Epipelagic species of Leptolina and Trachylina 97 



Bathypelagic species of Leptolina and Trachylina 9^ 



Summary of the zoogeographical results 104 



References ^°" 



Tables "° 



Index of Genera and Species 127 



Plates I-VII following page 12% 



NEW OBSERVATIONS ON THE ABERRANT MEDUSA TETRAPLATIA VOLITANS 

 BUSCH (published 28th February 1957) 



By William J. Rees and Ernest White 



Introduction P'^S^ ^3^ 



Acknowledgements ^3^ 



New Records of Tetraplatia ^2^ 



Geographical Distribution 132 



Vertical Distribution '35 



Seasonal Occurrence 136 



Hydrographic Correlations ^37 



Summary ^4° 



References ^4° 



7^^58 



