KOFOID AND MICHENER: DINOFLAGELLATES. 277 



GONIODOMA CRASSA, Sp. nOV. 



A large species with flaring narrow girdle, pointed antapex, and pitted, 

 porulate areas of plates greatly reduced and remainder covered by faint 

 irregular depressions. Body stout, ellipsoidal, with spreading girdle, and 

 antapex abruptly contracted to a stout, asymmetrical, blunt projection. 

 Length 1.07 transdiameters. Epitheca less than hypotheca, dome-shaped, 

 spreading immediately at the girdle, its altitude 0.47 transdiameter. Apex 

 broadly rounded, apical area triangular, with circular, sunken platelet. Hypo- 

 theca of similar form but fuller upon the left side and contracted distally to a 

 stout, blunt, asymmetrical projection deflected to the right, 0.07 transdiameter 

 high and 0.14 across its base. Girdle very narrow, 0.038 transdiameter 

 across, descending, displaced distally 2 girdle widths, distal end deflected 

 posteriorly in a sweeping curve and the proximal end abruptly curved in the 

 same direction, deeply impressed, V-shaped. Ventral area short and wide. 

 Apical plates small. Antapicals 1"" and 3"" exposed ventrally, and 2"" 

 dorsally. Surface with faint ridges along sutures, pitted, porulate areas 

 reduced to about one fourth of each plate, remainder with faint depressions 

 of irregular shape and distribution and without pores. No lists or spines. 

 Wall thick. 



Length, 94 fi; transdiameter, 88 /x. 



Sta. 4739. 



Protoceratium (Bergh) Kofoid emend. 



Plate formula 2', a , 6"(?), 6(?), 6'", 0", 3"". Apical 1' narrow, mid- 

 ventral, 2' large encircling rest of anterior end. Apical area present as in 

 Gonyaulax, sometimes obscured in the mesh. No anterior intercalaries. 

 Precingular 1' minute (always present ?). Postcingular Y" small. Posterior 

 intercalary probably shifted into antapical group. Antapicals 1"" and 3"" 

 nearly bilaterally symmetrical, 2"", large, dorso-terminal. Surface coarsely 

 and heavily marked with polygonal mesh of heavy ribs. 



Protoceratium cancellorum, sp. nov. 



A large, remotely subglobular species with exceedingly coarse mesh. Length 

 1.08 transdiameters. Girdle section very broadly reniform. Epitheca 0.5 

 altitude of hypotheca, low dome-shaped, sides only slightly convex. Apex 

 rounded. Hypotheca laterally contracted immediately behind girdle, 0.3 

 wider dorso-ventrally than transversely, antapex broadly and symmetrically 

 rounded. Girdle descending, displaced scarcely 1 girdle width, without 

 overhang, its furrow deep and narrow, with heavy hyaline non-ribbed lists. 

 Ventral area 0.5 transdiameter in total length, arched to the right with hyaline 

 fin on right margin. Surface with Remarkably coarse polygonal meshwork, 



