Vol. 3] Kofoid. — Dinoflagellata — New Species. 313 



Dinophysis diegensis, sp. no v. 



PI. 33, figs. 57-61. 



D. homunculus (in part), Stein ('83), Taf. 21, Fig. 8. "Ein 

 junges Individuum. " 



A small species with elongated, laterally compressed body, 

 pointed antapex, but lacking the dorsal elevation found on D. 

 Jioni)(ncuU(s. 



The body is stouter than in D. homunculus, its length, ex- 

 cluding lists, being 2.5 times its dorso-ventral diameter. It is 

 much compressed laterally, its transdiameter being less than 0.5 

 of the dorso-ventral diameter. 



The epitheca is exceedingly low, being less than 0.5 of the 

 width of the transverse furrow in height and almost without con- 

 vexity. The hypotheca has its dorsal and ventral margins almost 

 parallel as far as the level of the posterior rib of the ventral fin. 

 There is a little convexity in the dorsal outline and a slight local 

 swelling in some individuals at the flagellar pore on the ventral 

 margin. From approximately at the level of the posterior rib 

 the posterior third of the hypotheca is contracted to a bluntly 

 rounded point. Both margins are concave, the dorsal more so 

 than the ventral. The antapex is rarely curved ventrally as in 

 forma curvata (PI. 33, fig. 58). 



The collar lists are lower and less oblique than in Stein's ( '83) 

 figure, being relatively heavy low ridges. The height of the an- 

 terior one about equals the width of the furrow and is higher 

 ventrally than dorsallj^ The posterior one is about half this 

 height and more flaring. The plane of the girdle is oblique to the 

 main axis postero-ventrally at an angle of 25°. The anterior 

 collar is closed ventrally across the suture between the valves by 

 a thin lamella. 



The longitudinal fin arises from the rib on the proximal angle 

 of the posterior collar and continues posteriorly for about 0.6-0.7 

 of the length of the body. The suture spine lies posterior to the 

 middle of the fin and a more or less prominent posterior spine 

 arises beyond the end of the longitudinal furrow. The fin in some 

 individuals continues beyond this spine and is shortly confluent 

 with the ventral margin. The fin crosses from the left to the 



