238 University of California Puhlicafioiis in Zoology. [Vol.8 



Wliitting (1899) as Goniodoma milneri. It has, however, a plate 

 formula identical with that of Gonyaulax polyedra and does not 

 exhibit the three antapicals characteristic of the genus Gonio- 

 doma. Gonyaidax ccratocoroides is closely related in plating to 

 this group, but because of its peculiar autapical spines is placed 

 in the subgenus Acantlxogonyaida.r. 



11. Gonyaulax polyedra Stein 



PI. 12, figs. 16-20; pi. 14, figs. 28, 29, 31; pi. 17, fig. 43. 

 Blepharocysta splendor maris Ehrenberg (1873), in part, pp. 3-4 



(of reprint), pi. 1, figs. 11, 12 only. 

 Gonyaulax polyedra Stein (1883), p. 13, pi. 4, figs. 7-9. 

 G. polyedra Blitschli (1885a), p. 545, pi. 26, figs. 20, 21; (1885b), 



pp. 932-933, 950-953, 1020, pi. 52, figs. 3a, b. 

 G. polyedra, Schiitt (1896), p. 21, fig. 29. 

 Gonyaulax sp., Torrey (1902), pp. 187-192, figs. 1-3. 

 G. polyedra, Okamura (1907). p. 132, pi. 5, figs. 35a-c (^ Gotiiodoma 



acuminatum Stein). 

 G. polyedra, Paulsen (1907), pp. 7-8, fig. 5; (1908), pp. 28, 31, 33, 



fig. 40. 



Diagnosis : A small, angular, polyhedral species, with ridges 

 along sutures, equatorial girdle displaced 1-2 girdle widths, 

 regularly pitted, rugose surface, four apical and two intercalary 

 plates, the right apical 4' minute. 



Description: Body polyhedral, subconical anteriorly, truncated pos- 

 teriorly, its length 1.15 transdiameters, the ventral face scarcely exca- 

 vated. The epitheca has both shoulders angled at the apical-precingular 

 suture; its greatest altitude is about 0.6 transdiameters. There is no 

 distinct apical horn. The hypotheca is more angular, sides straight or 

 nearly so, contracted regularly to a broadly truncated antapex 0.4 trans- 

 diameter in width, its greatest altitude almost 0.5 transdiameter. The 

 girdle section is nearly circular. 



The girdle is nearly equatorial descending, displaced distally 1 to 2 

 girdle widths, without overhang, and in some cases even parted 0.5 girdle 

 width, deeply impressed, guarded by low ridges with coarsely and 

 abundantly ribbed lists. Its ends are sometimes slightly curved pos- 

 teriorly in some individuals. 



The ventral area or longitudinal furrow is broad, not deeply excavated, 

 widening posteriorly to 1.5 girdle widths, its rounded posterior margin 

 slightly indenting the antapex. It is nearly straight. 



The plate formula is 4', 2», 6", 6, 6'", 1p, 1"". The formula here given 

 for the apical region differs from that given by Blitschli (1885a, 1885b), 

 Torrey (1902). and Paulsen (1907, 1908), in that here as in other species 

 of Gonyaulax and Peridinidae generally we designate as apieals (see 

 Kofoid 1909b) only those plates which reach the apex and as inter- 



