1910] Kofoid: A Revision of tin Genus Ct ratocorys. 185 



needs of flotation and orientation rather than upon mimicry of 

 an objectionable model and consequent survival by natural 

 selection. 



Taken at San Diego and Naples. Widely distributed in warm- 

 temperate and tropical seas. 



Described by Gourret (1883) as a Dinophysis jourdani and 

 again by Daday (1888) as D. armata and shifted to the related 

 genus Phalacroma by Schiitt (1895). In 1883 Pouchet describes 

 and figiires as Dinophysis galea a complex of four species belong- 

 ing in three cases to the genera Phalacroma and Ornithocercus, 

 while the fourth (the third in the unnumbered row) is possibly 

 Ceratocorys jourdani. Klebs shortly afterward (1884) finds 

 Dinophysis jourdani at Naples and states that it appears to him 

 to be the same as Stein's Ceratocorys horrida but that Gourret 

 has more correctly established its systematic position in Dino- 

 physis. 



Entz (1902) endeavored to show that this was a connecting 

 link between the two genera Phalacroma ami Ceratocorys belong- 

 ing to two different families, and even that C. horrida was a 

 "Wachsthumform," of Phalacroma Ceratocorys as he designated 

 this new connecting link. His evidence, as far as it goes, shows 

 rather that Phalacroma jourdani is a Ceratocorys and had he 

 fully analyzed the plates the transition to that genus would 

 doubtless have been completed. I find no evidence whatever to 

 support his hypothesis that C. horrida is in any way a part of the 

 life-cycle of C. jourdani. or to substantiate Murray and Whit- 

 ting's very tentative suggestion that the form they figure (pi. 30, 

 fig. 5a) is an "encysted" stage of C. horrida. It is a typical 

 C. jourdani, a species not elsewhere recognized by them. 



Grateful acknowledgments are made to the Smithsonian 

 Institution and to the authorities of the Naples Zoological Sta- 

 tion, as well as to the Marine Biological Association at San Diego 

 for facilities in connection with this paper. 



