KOFOID AND SWEZY: UNAKMORED DINOFLAGELLATA 141 



hypocono is an irregular saeklike body with a deep groove on the proximal part of the ventral 

 face and a shallow one on the distal part of the dorsal face. The antapex is broad and rounded. 



The girdle lies at a distance from the apex on the dorsal and ventral sides of 0.3 and 0.4 of 

 the total length of the body respectively. The furrow is wide, about 0.06 transdiameter, and is 

 deeply impressed, undercutting the anterior border and smoothly curving out to the posterior 

 one. Both lips are outlined by a double-contoured, blue green line. The exact relations of the 

 sulcus are difficult to distinguish. It seems to invade the epicene at the base of the trough which 

 indents its ventral face. Posteriorly it extends to within a short distance of the antapex. The 

 anterior flagellar pore is found at the junction of girdle and sulcus, and the posterior pore a 

 short distance in front of the antapex. 



The nucleus is an ellipsoidal body filled with moniliform chromatin strands. It is slightly 

 posterior to the central part of the organism. Its axis is about 0.36 transdiameter in length. 



The cytoplasm is finely granular and rather dense in appearance. In the central part of the 

 body is a mass of dark, refractive granules. Anteriorly is a large body of greyish color, pre- 

 sumably a food mass, and nearer the center a larger, reddish brown body. Posterior to the 

 nucleus are other bodies grey and reddish brown in color. A few small spherules and minute 

 refractive granules are scattered through the remainder of the cytoplasm. The general color 

 of the organism is dull grey green. The surface of the body is marked by a few double-contoured 

 lines or ridges, about five on one face of the hypoeone, fewer on the epicone. These extend from 

 the girdle to the apices. 



DiMENSioxs. — Length, 102/^; transdiameter, 63m; axis of iiiicleiis, 23^-. 



OccrEREXCE. — This species was first seen in a surface hattl made at the end 

 of tlie pier at the Biological Station at La Jolla, California, June 26, 1917. On 

 July 25 it was taken in a haul 11 miles offshore, from 80 meters to the surface 

 and in a surface temperature of 21-75 C On July 27 it was noted in a haul 

 taken 4 miles otfshore, from 80 meters to the surface and in a surface temper- 

 ature of 21-9 C. 



Comparisons. — This is an aberrant species, AmpJiidinmm-\ike in the relation 

 of ejDicone and hji^ocone, yet possessing charactei's which clearly mark it off 

 from the other species of that genus. In one individual noted, a stout, laterally 

 projecting tentacle was thrust out from the distal part of the sulcal area. This 

 greatly resemljled the prod of Erythropsis. The individual possessing it was 

 not active, so that nothing can he said as to its motility or normality. It was 

 possi1)ly only a temporary protoplasmic process. 



Amphidinium galbanum sp. nov. 



Plate 1, figure 4 ; text figure U, 29 



DiAOXosis. — A small species with sul)cylindrical body, its length, 1.92 trans- 

 diameters ; girdle anterior, displaced 0.4-t transdiameter, sulcus extending from 

 near apex to antapex ; surface furrowed ; bright green yellow chromatophores. 

 Length, 48m. Pacific off La Jolla, California, July. 



Description. — The body is small, subcylindrical with the anterior end forming a conical cap, 

 the posterior end rounded, slightly wider anteriorly, its length 1.92 transdiameters at the widest 

 part. The hypoeone greatly exceeds the epicone in size, its length being greater by 0.63. The 



