298 University of California Publications in Zoology. [Vol. 8 



general rugosity. These is much variation also in length of apical 

 and antapical horns. 



Comparisons : This species is readily distinguished from all 

 those in the subgenus Fusigonyaulax (see Univ. Calif. Puhl. 

 Zool., vol. 8, no. 4, p. 246) by its stout apical and antapical horns 

 and by the presence of four instead of three apicals, and by its 

 anterior intercalary plate. As yet there is but the one species in 

 the genus. 



Distribution: Described by IMurray and Whitting (1899) 

 from the tropical Atlantic between 42° N and 26° S, from the 

 Caribbean and the Azores; and later recorded by Cleve (1902) 

 from the tropical Atlantic between 28° N and 32° S. Also 

 reported by Schroder (1900) from Naples, by Entz (1902, 1905) 

 from Quarnero, and by Pavillard (1907) from the Gulf of Lyons. 

 Cleve (1903) reports it from the ^Mediterranean, Red and Arabian 

 Seas, and Karsten (1907) in two localities near the equator in the 

 Indian Ocean. 



Taken at surface ten miles off Point Loma, November 12, 1904, 

 and occasionally elsewhere in San Diego region in October-Decem- 

 ber in oceanic plankton of subtropical facies in association with 

 Ceratocorys horrida, Ceratium reticulatum and C. trichoceros. 



For papers cited see bibliography of Article 4 in this volume. 



Zoological Laboratory, University of California. 

 Transmitted June 13, 1191. 



