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UNIVERSITY OF CALIFORNIA PUBLICATIONS 



IN 



ZOOLOGY 



Vol. 11, No. 12, pp. 307-328, pis. 13-15 February 21, 1914 



THE STRUCTURE OF THE OCELLI OF 

 POLYORCHIS PENICILLA TA 



BY 



ETTA VIOLA LITTLE 



INTRODUCTION 



The genus Polyorchis was founded by Alexander Agassiz in 

 1862 (in L. Agassiz, 1862) to include the California species 

 pcmcillatum which Eschscholtz (1829) had described and placed 

 in the genus Mclicertum. Haeckel (1880) claimed that by right 

 of priority the generic name Melicertum should be retained for 

 this species. Lankester (1900) places the genus Polyorchis in 

 the family Cannotidae of the Leptomedusae, while Fewkes (1889) 

 placed it among the Anthomedusae. The latter says : ' ' There 

 seems to be no doubt that Polyorchis belongs to the true Antho- 

 medusae and that it is closely allied to Sarsia, as suggested by 

 rows of meridionally placed nematocysts on the outer wall of 

 the bell." And again, "Polyorchis is the largest medusa of 

 tubularian hydroids or Anthomedusae yet found in American 

 waters." Mayer (1910) correctly a.ssigns Polyorcliis to the 

 Leptomedusae, family Thaumantiadae, without lithocysts, sub- 

 family Polyorchinae, with diverticula on radial canals ending 

 blindly. 



Haeckel (1880) divides the genus into three species. /'. piii- 

 natus is described as being distinguished from penicillata by the 

 smaller number of lateral branches of the radial canals and 

 the larger number of gonads and tentacles, there being eight 

 gonads on each of the four radial canals, and forty tentacles of 

 the same length in a single row. On the other hand P. pcnicil- 



MAR A 



