Vol. XIV. December, igoy. No. 



BIOLOGICAL BULLETIN 



ON THE LIGHT RECEPTIVE FUNCTION OF THE 

 MARGINAL PAPILLAE OF GONIONEMUS. 1 



l. murbach. 



Introductory. 

 On the oral or subumbrellar margin of the jellyfish Gonione- 

 mus' 2, there are somewhat spherical or cordate papillae, corres- 

 pondingin number to the tentacles, and almost directly underneath 

 the proximal ends of the tentacles. They are a bright translu- 

 cent rust color with darker pigment lining the interior. The 

 cavity is a continuation or pouch from the circular canal, thus 

 insuring abundant nourishment for them. To distinguish them 

 from marginal bodies, by which name Ccelenterate writers gen- 

 erally designate the otocysts, these organs are called marginal 

 papillae. Nutting 3 calls them sense bulbs, and Hargitt 4 and 

 Goto 5 refer to them as "basal bulbs," Hargitt 4 describing them 

 as " of brownish color delicately tinged with bright green." He 

 also ascribes visual function to them. 6 The beautiful green spots 



1 To the management of the Marine Biological Laboratory I owe the material 

 assistance enabling me to carry on my work and for this I am much indebted. 



2 The Woods Hole species is, of course, the one in question. Hargitt in " The 

 Medusee of the Woods Hole Region," p. 53> under the synopsis of Gonionenius mur- 

 bachii Mayer, says: "This species was first described by A. Agassiz in 1862 from 

 the Pacific coast. In 1895 a species was found at Woods Hole and supposedly iden- 

 tified with the Pacific species by Murbach, but it has since been classified as a distinct 

 species by Mayer." This " supposition " is gratuitous. By using only the genus 

 name in my report I meant to indicate my doubt about the identity of the species. 



3 Nutting, C. C. ('01), "The Hydroids of the Woods Hole Region," U. S. Fish 

 Commission Bulletin, 1899 (Publ. 1901). 



* Hargitt, Charles W. ('04), "The Medusse of the Woods Hole Region," 

 Bulletin of the Bureau of Fisheries, Vol. XXIV., 1904. 



5 Goto, Seitaro ('03), "The Craspedote Medusa Olindias and Some of its Natural 

 Allies," The Mark Anniversary Volume, Art. I., pp. 1-22, 1903. 



6 Loc. cit., introduction. 



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