KOFOID AND MICHENER: DINOFLAGELLATES. 271 



The polygramma group. 

 Characterized by prevalence of linear markings. 



GONYAULAX MINUTA, Sp. nov. 



A minute subspheroidal species with barely suggested apical horn with 

 oblique apex. Length 1.1 transdiameters. Apex tilted to the left. Hypo- 

 theca hemispherical. Girdle descending, displaced 1 girdle width. Ventral 

 area not indenting epitheca, terminating posteriorly in broadly rounded 

 expansion. Ventral pore in apical 3'. Plate formula 3', a , 6", 6, 6'", l p , 

 \"" . Apical 1/ widened posteriorly; precingular 6" nearly square; post- 

 cingular 1' minute, triangular; posterior intercalary wide. Surface smooth 

 or faintly marked with linear striae. Girdle striate. No spines or lists. 



Length 20-25 /z; transdiameter, 18-20 /z. 



Sta. 4720. 



GONYAULAX PAVILLARDI, Sp. nOV. 



A small rotund or subangular species with predominantly linear markings. 

 Length 1.1 transdiameters. Body rotund, angled at apical-precingular 

 suture. Epitheca gradually contracted into short (1.5 girdle widths) squarely 

 truncate, apical horn. Hypotheca asymmetrically rounded, fuller on left 

 side. Ventral pore on apical 3'. Girdle descending, displaced 1 girdle width, 

 no overhang. Ventral area acutely and deeply indenting the epitheca, nearly 

 straight, its posterior plate subcircular, reaching postmargin, and often bear- 

 ing several antapical spinules. Plate formula, 3', a , 6", 6, 6'", l p , 1"". 

 Apical 1', narrow, widened posteriorly; precingular 6" quadrangular; post- 

 cingular V" very slender, less than 0.5 girdle width across; posterior inter- 

 calary wide, antapical 1"" mainly dorsal in exposure. Surface sparingly 

 reticulate with mainly longitudinal markings. Double ribs along sutures. 

 Pores in lines. 



Length, 48 y.\ transdiameter, 44 ft. 



Sta. 4717. 



GONYAULAX RETICULATA, Sp. nOV. 



A small to medium sized species resembling G. polygramma Stein but 

 entirely without the characteristic linear markings. Body rounded, in smaller 

 forms scarcely angled at apical-precingular suture. Length 1.3 transdiame- 

 ters. Epitheca contracted to a stout apical horn with truncate apex. Hypo- 

 theca subhemispherical. Girdle descending, displaced 1.5 to 2 girdle widths, 

 no overhang. Ventral pore on apical 3'. Ventral area indents epitheca, 

 slightly curved, enlarged distally to left, reaching postmargin. Plate formula, 



