NEW PHOSPHORESCENT ORGANS IN 

 PORICHTHYS. 



BY FREDERICK C. TEST. 



(WITH PLATE IV.) 



At the Suggestion of Dr. D. S. Jordan, the investiga- 

 tions detailed in the following pages were made, under 

 the direction of Dr. J. S. Kingsley, during the year 1888. 



PoTiclithys margaritatus is found on the Pacific coast, 

 where it is generally, if not solely, a shore fish. It has 

 received its common name of "midshipman" from the fact 

 that it is covered with rows of what are described as "shin- 

 ing pores" in Jordan and Gilbert's " Synopsis of North 

 American Fishes." These "shining pores" were supposed 

 to bear some resemblance to the buttons on a midship- 

 man's jacket. 



My work was begun, to ascertain the true structure of 

 these "shining pores," and to see if they really were phos- 

 phorescent organs, as Dr. Jordan thought they might be. 

 The problem was all the more interesting in that while 

 almost all fislies known to bear phosphorescent organs be- 

 long to the abyssal depths of the ocean, this, as I have 

 Said, is a shallow-water fish. 



The technique pursued was that usually followed in his- 

 tological researches, serial sections being used, stained in 

 toio with alum cochineal. The material on which I worked 

 was unfortunately not in good condition for histological in- 

 vestigations, and only after the plate was engraved, was I 



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