260 Mr. C. O. Waterhouae on neiv Coleoptera. 



dependent upon it, viz. that there are bathymetric limits in 

 the ocean, even to nomadic animals apparently as helpless as 

 the Medusaj. 



In closing my short discussion of the question of deep-sea 

 nomadic Medusan life it may be said that, as far as the data 

 thus far gathered go, neither the recorded depths nor the 

 structure of the genera considered demonstrates that we have 

 a serial distribution of free Medusae in biithymetrical zones. 

 While our present information is insufficient to answer the 

 question, it seems to me that the case is much stronger than 

 the arguments which can be advanced in its support. There 

 is little doubt that Medusan life has bathymetrical limita- 

 tions. Our well-known surface Medusas probably cannot live 

 at great depths, and their places are probably taken there by 

 others ; still, until there are more exact data bearing on this 

 conclusion, it cannot be demonstrated to be true. What is 

 now needed is, in the first place, an accurate determination 

 of the depth at which Medusse of different genera are cap- 

 tured, and secondly a more accurate study of the peculiarities of 

 anatomy and development of those which are supposed to be 

 thus limited in habitat. It is also equally necessary that the 

 surface-fauna should be better known for comparison. There 

 are at present a few marine stations in the Mediterranean and 

 North Atlantic where the study of surface-life is zealously 

 prosecuted; but it is only when the Miiller's net has been 

 used with equal zeal in the South Atlantic, the Indian Ocean, 

 and Pacific that we can have a basis to work upon. An 

 exploring vessel on a cruise through these waters is not 

 enough. It is a reconnaissance. There must be established 

 permanent marine stations where the study will be carried on 

 year after year for a long time in one locality. 



XXXI. — New Species c/Lucanidfe, Cetoniida, and Bupres- 

 tidas in the British Museum. By Chaeles O. Water- 

 HOUSE. 



Lucanidae. 



Eexarthrius Davisoni, n. sp. 



Color lAiccini ccrvi et eodem sat similis, cajDite thoraceque magis 

 rugosis ; mandibulis elougatis, nitidis, nigris, apicem versus 

 inclinatis, intus quadridentatis, dente basali valido. c? . 



Long. 23-26 lin. : mandib. lli-lS liu. 



