1911] Kofoid: The Genus Gonijaulax. 231 



regions between the striae are freely areolated or sometimes reticulated, 

 with scattered pores with a tendency to linear grouping along the ribs. 

 The ribs lie on suture lines in some cases, but several ribs may appear 

 on one plate. The ventral area is sparingly porulate. The girdle ridges 

 may be faintly armed with lists, and low denticulate lists may guard 

 the longitudinal furrow. At its posterior end the denticulations become 

 finned antapical spines sometimes 1.5 girdle widths in length and 1-3 

 in number. There is often none, and the single one or the largest where 

 several are present is at the left. The suture lines are sometimes marked 

 by narrow intercalary bands. 



Contents dense, chromatophores crowded, yellowish to dark brown, 

 elliptical or sausage-shaped, sometimes linear and radiating from the 

 center of the cell mass. The theca is frequently opened by parting of 

 the apical plates and the contents escape in a membranous envelope 

 which is soon differentiated into a new theca. In this stage it is faintly 

 and abundantly striate longitudinally and has been designated by Lem- 

 niermann (ISSS^) as G. schuetti on the basis of Schiitt's (189.5) figures. 



Dimensions : Length, 42-75;u. ; transdiameter, 88-48;u. ; length 

 of longest antapical spine, 2-8/^ ; width of girdle, 4-5/a. 



Variation : This widely distributed species varies toward 

 both G. tttrbipici, the next smaller member of the series, and 

 toward G. kofoidi and G. pacifica, the larger ones. This varia- 

 tion is expressed in a shorter or longer apical region, in suppres- 

 sion or extension of the antapical spines, and in increasing devel- 

 opment of the left antapical spine. There is also great variation 

 in the development of surface markings. In highly striated forms 

 the number of major lines seems to be fairly constant and in the 

 main the species is one of the most easily recognized ones in the 

 genus. 



SvNONOMY : Originally described by Stein (1883) from the 

 Atlantic and Pacific. Prior to the appearance of Stein's paper 

 (November, 1883), Pouchet (July-August, 1883) published a 

 figure of a Goniiaulax which is undoubtedly G. polygramma 

 under the name of Protopcridinium pyrophorum and indicated 

 in his discussion that it was provisionally regarded as identical 

 with Ehrenberg's (1836) fossil Peridiuium (?) Glenodinium (?) 

 pyrophorum. It is, however, wholly different and Stein's name 

 becomes applicable. Lemmermann's (1899) designation, as a 

 distinct species, of the thin-shelled sutureless forms following 

 ecdysis figured by Schlitt (1895), should be dismissed, but his 

 later (1907) designation of Stein's figures 16 and 17 as G. steini 



