KOFOID AND MICHENER! DINOFLAGELLATES. 273 



square. Posterior intercalary horizontally elongated. Surface smooth with 

 few scattered pores or numerous small ones. 

 Length 20 m; transdiameter, 18 n. 



Sta. 4720. 



Subgenus Steiniella (Schiitt) Kofoid. 



The fragilis group. 

 Characterized by apex carried on to dorsal surface and very fragile theca. 



GONYAULAX INCLINATA, Sp. nOV. 



A large, broadly rounded, asymmetrical species with short, slender, oblique, 

 apical horn. Length equals transdiameter. Body rotund, flattened poste- 

 riorly. Epitheca contracted abruptly into a short (2 girdle widths), conical, 

 truncate, apical horn tilted (15°) to right. Hypotheca asymmetrical. Ant- 

 apex concave, with list with numerous spinules. Girdle descending, displaced 

 2.5 girdle widths, ends not meeting in median line by 1.5 girdle widths. Ven- 

 tral area deeply and squarely indenting epitheca, nearly straight, scarcely 

 widens distally to postmargin. Plate formula 4', a , 6", 6, 6"' (?), 1", 1"". 

 Apical 1' widening posteriorly to square junction with ventral area; precingu- 

 lar 6" pentagonal; posterior intercalary large; antapical 1"" relatively small. 

 Surface minutely and prominently reticulate. Pores in angles of areas. 



Length, 75 n; transdiameter the same. 



Sta. 4737. 



The bispinosa group. 



Characterized by two widely separated prominent antapical spines, and 

 premedian girdle. 



GONYAULAX BISPINOSA, Sp. nOV. 



A very large, elongated, rotund species with two prominent antapical 

 spines whose fins extend to the girdle. Body elongated, length 1.3 transdiam- 

 eters. Girdle premedian, epitheca only about half the length of hypotheca. 

 Epitheca convex, no apical horn, greatly elongated apical carries closing 

 platelet on to dorsal face. Hypotheca constricted behind girdle, then expand- 

 ing to rotund sac-like antapex. Girdle descending, displaced 2 girdle widths, 

 scarcely impressed, with high hyaline lists, no overhang. Ventral area very 

 narrow as far as to the large elliptical posterior plate which does not reach to 

 antapex. Plate formula 4', 1° (?), 6", 6, 6'", l p , 1"". Apical 1' very narrow, 

 2' and 3' wide, and 4' narrow, precingular 6" quadrangular; postcingular V" 

 short; posterior intercalary and antapical V" very large. Surface smooth, 



