314 University of California Publications. [Zoology 



right valve at the suture spine. The pore and longitudinal fur- 

 row lie upon the right valve. Flagellar pore more posteriorly 

 located than usual in DinopJiysis, being near the base of the 

 suture spine. 



The thecal wall is delicate and hyaline with numerous fine 

 pores, 12-20 across the valve. The suture is marked by a promi- 

 nent line. 



The plasma is hyaline, and contains a posteriorly located 

 nucleus, and scattered irregular yellowish ehromatophores. 



In the many individuals of this species which I have seen, no 

 evidence appears that this is a "young" individual of D. homun- 

 culus, as Stein ( '83) states. It appears to be a perfectly distinct 

 species of small size, different form and habitus. It varies in the 

 outline of the antapical region, the protuberance of the flagellar 

 pore and the distinctness of the pores on the valves. 



Length, 55-110/*; dorso-ventral diameter, excluding fin, 23- 



Eare in neritic plankton in the summer oft* Southern Cali- 

 fornia. Taken off San Diego and La Jolla, and in San Pedro 

 Harbor. 



Dinophysis ellipsoides, sp. nov. 



PI. 33, fig. 56. 



A small hyaline species with ellipsoidal, laterally compressed 

 body and low collars. 



Body symmetrically ellipsoidal, its length 1.6-1.7 times the 

 greatest dorso-ventral diameter. Transdiameter about 0.3-0.4 of 

 the dorso-ventral diameter. Epitheca very low, scarcely convex. 

 Hypotheca broadly and symmetrically rounded at the antapex, 

 equally convex dorsally and ventrally except in the region ante- 

 rior to the flagellar pore which is slightly concave. Girdle nearly 

 perpendicular to the main axis. Collar lists low and flaring, the 

 posterior lower than the anterior, and diminishing in elevation 

 toward the distal end. Anterior collar faintly ribbed. Longi- 

 tudinal fin with three ribs, one at the anterior angle, a middle 

 suture spine and a recurved posterior one. The fin is abruptly 

 decurrent behind the posterior spine. 



Thecal wall very thick but exceedingly hyaline. Sagittal su- 

 ture scarcely marked, pores minute, about 20 across the valve. A 



