362 MEMOIRS OF THE UNIVERSITY OF CALIFORNIA 



DiMEXsioxs. — Length, 39a* ; trausdiameter, 31m ; axes of nucleus, 15f and 12f*. 



OcciTRRExcE. — Tliis was taken Jidy 26, 1917, with a Xo. 25 silk net, 2.5 miles 

 off La Jolla, California, in a haul from 80 meters to the surface, in a surface 

 temperature of 21-6 C. 



Comparisons. — This species lies midway between C. vinctum (fig. HH, 3) 

 and C. gemination (fig. HH, 1) in the degree of as^inmetry and flattening. It 

 has more torsion than C. vinctum by nearly 0.5 turn, is only half the size and 

 has a horizontal extension of a longitudinal antapical loop of the sulcus. It 

 is also smaller tliau C. (jcminatum, lacks its distinct ochraceous chromatophorcs, 

 and has somewhat more torsion of the sulcus. 



This species belongs to the C. strangulatum group of the subgenus Cochlo- 

 diniiim, resembling other members of that group in the amount of torsion of 

 the body, as indicated by the niunber of turns of the girdle, but differing from 

 them in the t^^pe of si^iral formed by the girdle. About 0.5 of the entire length 

 of the girdle encircles the anterior end, giving to the epicone a relatively small 

 proportion of the anterior surface of the body. 



Cochlodinium constrictum (Schiitt) Lemm. 



Text figure GG, 13 



Gymnodinium constrictum Schiitt (1895), pi. 26, fig. 93i. 

 CocJilodinium constrictum, Lemmermann (1899), p. 360. 



Diagnosis. — A medium sized species vnth irregularly biconical body, its 

 length 1.38 transdiameters ; girdle salient, a descending left spiral of about 

 0.18 turns, displaced about 0.76 trausdiameter; sulcus extending from apex to 

 antapex, with torsion of about 1 turn ; color, rose pink. Length, 90/*. Atlantic 

 ( ?) or Bay of Naples. 



Description. — This description of this species is hased on a single figure of Schiitt (1895, 

 pi. 26, fig. 93i ) , the data of which are inadequate on some points, such as the anterior termination 

 of the sulcus and girdle and the distal end of the girdle. From a comparison of his figure and 

 other species of CocModinium one may approximately locate the position of the points mentioned. 

 This has been done in the following description. 



The body is roughly biconical with rounded apices, salient girdle and constricted sulcus, length 

 1.38 transdiameters at the widest part, which is submedian. The hypocone exceeds the epicone in 

 size. The epicone has a length probably of about 0.17 above the proximal border of the girdle and 

 from its distal extremity of about 0.7 of the total length of the body. Its sides are unequally 

 rounded with a depression on the dorsal face, which may be the anterior end of the sulcus on the 

 ventral side, incorrectly drawn as on the dorsal surface. The apex is broadly rounded and blunt. 

 The hypocone diminishes to about half its width a short distance below the girdle, beyond which 

 it is rounded with a broad, blunt antapex. 



The .junction of the girdle and sulcus occurs a short distance below the apex. It follows a 

 descending left spiral course around the body and meets the distal end of the sulcus about 0.3 

 of the total length of the body from the antapex. The girdle occupies a high, ridgelike portion 

 of the body, from which the surface slopes away on either side. The girdle itself is apparently 

 shallow with smooth borders. 



