272 bulletin: museum of comparative zoology. 



3', a , 6", 6, 6"', l p , 1"". Apical 1' very narrow, curved to right posteriorly; 

 precingular 6" quadrangular; postcingular V very narrow; posterior inter- 

 calary long and narrow. Without lists, with or without two short, finned, 

 antapical spines. Surface coarsely and regularly reticulate. Sutures ribbed, 

 often marked by intercalary bands. 



Length, 50 to 65 n) transdiameter, 45 to 50 /x. 



Sta. 4724. 



The sphacroidea group. 

 Characterized by spherical form. 



GONYAULAX SENTA, sp. IIOV. 



A small species of spheroidal form, impressed girdle, and spinous hypotheca. 

 Length 1.1 transdiameters. Epitheca with low (0.5 girdle width) squarely 

 truncate apical horn. Hypotheca subhemispherical. Girdle descending, 

 displaced 2 girdle widths, with slight overhang. Ventral area acutely indents 

 epitheca^ straight and narrow, and scarcely excavated posteriorly, not in- 

 denting antapical plate. No ventral pore. Plate formula, 3', a , 6", 6, 6'", 

 l p , 1"". Apical 1' minute, not reaching anterior plate of ventral area, apical 

 3' short; precingular 6" small, triangular; postcingular V" and posterior 

 intercalary small; antapical V" very large. Girdle impressed, with low fins. 

 Surface of epitheca minutely and faintly areolated, and with faint scattered 

 reticulations, that of hypotheca without reticulations, abundantly covered 

 with minute spinules, about seventy-five on its ventral face, longest on the 

 antapical plate. 



Length, 58 n) transdiameter, 52 n. 



Sta. 4683. 



GONYAULAX PAUCULA, Sp. IIOV. 



A very minute species with subspheroidal form, feebly developed girdle, 

 and smooth surface. Body nearly spheroidal, length 1.1 transdiameters, 

 girdle section circular. Epitheca less than hypotheca, its altitude about 0.5 

 transdiameter. Hypotheca slightly exceeding a hemisphere, its altitude about 

 0.6 transdiameter. Girdle descending, displaced nearly 1 girdle width, 

 without overhang. Its furrow not impressed, slight ridge at its anterior 

 margin, no posterior structure to mark suture or at most a feeble ridge, as in 

 Heterodinium. Ventral area not impressed, not indenting epitheca, not 

 spreading distally, its total length 0.6 transdiameter. Plate formula 3', 3 a , 

 6", 6 (?), 6'", 1* 1"". Apical 1' curved or angled to the left. Intercalaries 

 dorsal, 2 a smallest. Precingular 6" quadrangular, postcingular V" nearly 



