228 University of California PuhUcatious in Zoology. [Vol. 8 



7. Gonyaulax scrippsae sp. nov. 



Diagnosis: A small very rotund species with small apical 

 horn, much displaced girdle, surface with fine striations princi- 

 pally in the longitudinal direction. 



Description: Body subspheroidal, its length 1.12-1.15 transdiameters. 

 Dorso-ventral diameter equal to transdiameter. Epitheca subhemispheri- 

 cal, contracted abruptly at the apex to a short apical horn whose altitude 

 and diameter are each less than a girdle width, with an oblique apex 

 tilted toward the ventral face. Its greatest altitude is 0.6 to (i.7 trans- 

 diameters. Its sides are regularly convex without trace of angulation at 

 the shoulders. The hypotheca is nearly hemispherical, its greatest altitude 

 is about 0.6 transdiameter. There is no angulation at the antapex. 



The girdle is equatorial, descending, displaced 2 to 3 girdle widths 

 with an overhang of 0.1 to 1 girdle width. The furrow is deeply indented 

 with marginal ridges scarcely elevated above the body contour and 

 without lists. The ventral area or longitudinal furrow is sigmoid, rather 

 narrow. The ventral area makes a shallow rounded indentation into the 

 epitheca, is compressed almost to closure in its oblique course between 

 the girdle ends and widens beyond the girdle to 1.4 girdle widths. Its 

 posterior end is rounded and barily indents the antapical plate. 



The plate formula is 3', 0", 6", 6, 6'", IP, 1"". Apical 1' is a slender 

 plate expanded toward the apex at the apical-precingular suture and bears 

 at the apex the elliptical closing platelet (cl. pL, pi. 13 fig. 27). Apica] 

 3' bears the ventral pore (v. po.) very near the apex. Precingular 6" is 

 triangular and postcingular 1'" almost linear in form. Posterior inter- 

 calary IP is a relatively small plate in this species. The plates of the 

 ventral area in the intermediate region are obscured in the narrow fur- 

 row. The anterior plate {ant. pi.) is partially crossed by the anterior 

 girdle ridge and notched in its left ventral edge by the flagellar pore 

 (fl. po.). There are suggestions of several intermediate plates (int. pi.) 

 and a well-defined posterior plate (post, pi.) some distance behind the 

 distal end of the girdle. 



The surface is very characteristically marked with fine subparallel 

 lines which are mainly longitudinal but in some places are parallel to 

 the intercalary bands which are formed in all specimens I have seen 

 along the sutures. In cases of lightly marked specimens these lines are 

 regularly punctate (pi. 13, figs. 26, 27). In other cases the markings 

 are more of the vermiculate-reticulate type of heavier pattern though still 

 of delicate tracery and with more of a mesh work developed, especially 

 distally and on the hypotheca (pi. 16, fig. 38). Pores are not evident 

 except two marginal rows of minute ones just within the girdle ridges. 

 Sutures are very faint, marked by intercalary bands. No lists or fins 

 have been seen though in some cases two minute spinules (pi. 16, fig. 38) 

 appear on the antapex at junction points of the ventral area and anta- 

 pical plate. The girdle is abundantly marked by numerous parallel ribs 

 which connect the pores on its two sides. 



