300 University of California Publications. [Zoology 



Ceratium inclinatum. 

 Ceratium macroceros deflexum. 

 Ceratium mollis. 

 Ceratium ostenfeldi. 

 Ceratium reticnlatum spirale. 

 Ceratium schranhi. 

 Ceratium tenuissimum. 

 Ceratixim teres. 

 Gonyaulax pacifica. 

 Peridinium crassipes. 

 Peridinium minutum. 

 Peridinium multistriatum. 

 Peridinium rectum. 



OXYTOXINAE. 



Amphidoina biconica. 



DiNOPHYSIDAE. 



Dinophysis diegensis. 



Dinophysis diegensis forma curvata. 



Dinophysis ellipsoides. 



A m phisolen ia spin ulosa. 



Amphidinium sulcatum, sp. nov. 



PI. 22, figs. 1-3. 



Body is compressed oval in form, broadly oval in lateral view, 

 ellipsoidal in ventral view. The length 1.7 and the greatest dorso- 

 ventral diameter 1.4 times the greatest transdiameter. Body 

 widest (dorso-ventrally) about midway between the girdle and 

 antapex. 



The epitheca is low, its altitude 0.14 of the total length, 

 highest laterally and dorsally and hollowed out toward the longi- 

 tudinal furrow which passes dorsally beyond the apex. 



The hypotheca is broadly rounded posteriorly and very deeply 

 channeled ventrally by the longitudinal furrow which deepens as 

 it passes posteriorly from the flagellar pore. Its depth at the 

 pore is 0.25 of the dorso-ventral diameter at that level and at the 

 antapex it reaches the main axis. The right lip of this furrow is 

 somewhat higher than the left. 



The girdle is anterior in position, and the transverse furrow 

 is very deep, sinking obliquely posteriorly into the plasma. It 

 narrows distally to a slender channel displaced posteriorly the 

 width of the proximal end of the furrow. The flagellar pore lies 

 to the left of the tongue of the epitheca extended posteriorly be- 



