UNIVERSITY OF CALIFORNIA PUBLICATIONS 



IN 



ZOOLOGY 



Vol. 13, No. 10, pp. 239-241 September 25, 1914 



NOTE ON THE MEDUSAN GENUS 

 STOMOLOPHUS, FROM SAN DIEGO 



BY 



HENRY B. BIGELOW 



The following note is prompted by the receipt of several specimens 

 of Stomolophus, from San Diego Bay, California, where this 

 medusa was abundant during August and September, 1913, which 

 differ strikingly in color from their Atlantic ally, Stomolophus melea- 

 gris L. Agassiz. In the latter, which often swarms off the coasts of 

 the Carolinas, the gelatinous substance of the bell is bluish or yellowish, 

 the entodermal parts dull yellow, the exumbrella reticulated with 

 brown pigment, and its marginal zone thickly set with whitish or 

 yellowish dots. For an excellent account of ^S*. meleagris, see Mayer 

 (1910, p. 710). In the San Diego specimens the general color of the 

 bell is Prussian blue, pale at the apex, deeper at the margin; the 

 exumbrella is speckled with deep Prussian blue spots, which are most 

 numerous and largest near the margin, progressively fewer and smaller 

 towards the apex; but not altogether absent from any definite part 

 of the disc. Dissection shows that these dots are not on the surface, 

 but lie imbedded in the gelatinous substance of the bell, the largest 

 ones deepest. The oral arms are likewise pale Prussian blue ; the lips 

 whitish. 



But striking as is the color difference between the San Diego and 

 the Atlantic representatives of Stomolophus, it is not accompanied by 

 any structural differences which would warrant separating the former, 

 specifically, from the latter. Up to the present time four ''species" 

 of Stomolophus have been described, viz. : meleagris L. Agassiz, from 

 the South Atlantic Coast of the United States to South America; 

 fritillaria Haeckel, from the North Coast of South America (Suri- 

 nam) ; agaricus Haeckel, from the Pacific coast of Central America 



%. 



'?» lill 



