UNIVERSITY OF CALIFORNIA PUBLICATIONS 



IN 



ZOOLOGY 



Vol. 8, No. 5, pp. 287-294, pi. 18 September 14, 1911 



ON THE SKELETAL MORPHOLOGY OF 

 GONYAULAX CATENATA (LEVANDER) 



BY 



CHARLES ATWOOD KOFOID 



Through the kindness of Dr. K. M. Levander of the Univer- 

 sity of Helsingfors, Finland, I have been enabled to make an 

 examination of abundant material of his Peridinium cateiiatum 

 (see Levander, 1894a), and to compare its skeletal structure with 

 that of Gonyaulax described in the preceding paper {Univ. Calif. 

 Puhl. Zool., vol. 8, no. 4). The material placed at my disposal 

 is a collection made in the Gulf of Finland, ]\Iay 26, 1900, from 

 20 meters to the surface. It abounds in isolated individuals and 

 in chains of 2, 4, 6, or even 10 individuals. With this abundant 

 material, apparently in a similar phase of thecal condition, I have 

 been enabled to analyze the plates and thus to clear up some 

 uncertainties regarding the skeletal structure of the organism 

 and to demonstrate its close relationship to the genus Gonyaulax, 

 so close indeed that it seems best to include it herein. My most 

 cordial thanks are extended to Dr. Levander for his courtesy and 

 to Mrs. Josephine Rigden Michener for the carefvilly made 

 drawings which illustrate this paper. 



In Levander 's (1894a) account of the species he relates his 

 analysis of the plates and concludes that the organism on that 



