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Transactions. 



obtain between Nematolampas and the specimens of Lycoteuthis until we 

 come to a study of the distribution of the luminous organs. Even here 

 we find that each and every such organ described by Chun for L. diadema 

 finds its exact homologue in Nematolampas, but, continuing further, it- 

 appears that the Kermadec species possesses another entire battery of these 

 ''living lights" in addition. The comparison is well brought out in the 

 following table : — 



Position of Photophores. 



Ventral periphery of eyeball (5 on each) 



Tip of dorsal arms (1 on each) 



Tip of dorso-lateral arms (1 on each) 



Ventro-lateral arms (31+ on each) . . 



Tentacles (2 on each) 



Within pallial chamber — 



Anal 



Branchial 



Abdominal 

 Posterior extremity of body 



The complete homology of the complex intrapallial and tentacular 

 photogenic systems of the two species, coupled with the fact that all the 

 more important characters which differentiate Nematolampas {i.e., not 

 only the additional photophores, but the filamentous terminations of the 

 third-arm pair) take the form of features, as it were, superadded to those 

 already present in Lycoteuthis, at once suggests that in Nematolampas we 

 have either a more advanced stage in the ontogeny of the older genus, or 

 simply more perfect, material. I do not believe that either hypothesis, 

 however, is in accordance with all the facts. In the first place, the dimen- 

 sions of the type of L. diadema as given by Chun exceed those of the 

 smaller of the Kermadec specimens, and average only slightly less than those 

 of the larger ; in the second place, though the specimens before me are 

 not at all of the same size, they do not differ in any essential particulars ; 

 and, in the third place, L. diadema was captured and observed in the living 

 state by an investigator no less acute than Dr. Chun himself. 



It will be noted from the above account that Nematolampas regalis 

 possesses at least 90 definitely and symmetrically arranged photogenic- 

 organs, of which only 2 are unpaired, and it may be that there are yet others 

 which have escaped my search, the opacity of the tissues in preserved 

 material frequently rendering their detection exceedingly difficult. The 

 22 organs of Lycoteuthis, according to Chun, are constructed upon no less 

 than ten different principles, and are adapted for the production of lights 

 of several different colours and intensities. These ten types are all present 

 in the species from the Kermadecs, with at least two more as well. As 

 to the gorgeous appearance of this animal in life, we can only conjecture, 

 although Chun's lively description of his species gives us a most tantalizing 

 inkling of what we may expect. Cephalopods are bizarre creatures anyway, 

 but no more astonishing member of the group than this has rewarded one 

 of our collecting expeditions for a good many years. 



