PROCEEDINGS OF THE NATIONAL MUSEUM 



VOL. 76 



the following pages, and it is hoped by the author that, with these 

 observations supplementing the keys to the genera Myctophwm^ 

 Lampanyctus^ Diaphus, and Lmnpadeirm,^ already previously rendered 

 in the above-mentioned report, a not only practical but also reliable 

 foundation shall have been laid down for the future identification 

 of most of the formerly deplorably confused species pertaining to 

 the said four genera, which together constitute the subfamily Myc- 

 tophinae. 



Tlie abbreviations first introduced by Brauier (1906) for the 

 designation of the various groups or series of photophores will be 

 used throughout in the following notes, in accordance with the 

 practice now generally accepted in the modern literature on these 



Figure 1. — Diagrammatic drawing illustrating the terminology op the 

 luminous organs as applied to mi'ctophum californiense (compare with 

 pig. 4). l. sc. = supracaudal luminous scales. explanation of other 

 letters in the text 



fishes.' The accompanying diagram and list of the abbreviations 

 will sufficiently explain their use and meaning.^ 



PZ<9 = suprapectoral organ. 



PF(9 = subpectoral organs. 



P(9= thoracic organs. 



YL O — supra ventral organ. 



F(9 = ventral organs. 



/S^ (9 = supra-anal organs. 



^6> = anal organs. 



AO a^ii^. = antero-anal organs. 

 AO pc>s#. = postero-anal organs. 



P6»Z=postero-lateral organ (s). 



jPrc=praecaudal organs. 



The synoptic reviews of the four genera in question, given in the 

 above-mentioned report upon the Bingham Oceanographic CoUec- 



2 Zugmayer 1911, Taaning 1918 and 1928, Barnard 1925, Parr 1928, and others. 



= The fact that the abbreviations do not always correspond to the full terms employed 

 in the different languages has been intentionally disregarded in the literature for the 

 advantage of obtaining fixed international designations for the organs in question. 



