252 MEMOIRS OF THE UNIVERSITY OF CALIFORNIA 



trough clown the ventral face. The lengths of the epieone and hypoeone are about equal, but 

 the hypoeone, having a continuously wider transdiameter, exceeds the epieone in size. The 

 epieone has the shape of a cone of about 70^ with a blunt, rounded apex. The sides form almost 

 straight lines from the apex to the girdle. The middle tliird of the ventral face is deeply concave, 

 forming a trough in the bottom of which lies the sulcus. This becomes shallow anteriorly, fading 

 out at the apex. The length of the epieone is about 0.49 of the total length of the body. The 

 liypocone is truncate-pyramidal in outline and is less sjTnmetrical than the epieone. The sides 

 are concave-convex and form angles of about 25° with the longitudinal plane of the body. The 

 antapex is broad, about half the greatest diameter of the body, and is truncated by the broad 

 sulcal notch. 



The girdle is submedian in position, its distance from the apex being 0.49 of the total length 

 of the body. It forms a complete circle about the body, the ends meeting without displacement. 

 The furrow has a width of about 0.08 transdiameter and is deeply impressed. The anterior lip 

 is deeply undercut, the posterior side of the furrow gradually rounding out to the surface of 

 the body. The borders of the girdle are smooth. 



The sulcus extends from the apex to the antapex in a slightly sigmoid curve. It lies at the 

 bottom of a broad trough which indents the ventral face of the body. It is narrow, expanding 

 beyond the po.sterior flagellar pore both laterally and in deptli, forming a broad notch at the 

 antapex. The anterior flagellar pore opens at the junction of the girdle and sulcus. The 

 transverse flagellum traverses 0.95 of the entire length of the girdle. The posterior flagellar 

 pore is found slightly beyond the midpoint between the girdle and the antapex. 



The nucleus is a large, spheroidal body filled with moniliform chromatin strands. It is found 

 on the left side of the body slightly anterior to the equatorial plane. Its axis is about 0.47 

 transdiameter in length. 



The cytoplasm is very finely granular, clear and transparent. Sacklike pusules are usually 

 present at eitlier or both pores. Nutrition is holozoic, indicated by the presence of food bodies 

 in the CAi:oplasm. In the individual figured two food bodies were present. One was a large 

 grey-green, spheroidal body on the right side near the nucleus, the other was an irregular mass 

 in the posterior part of the body, mustard yellow in color. The general color of the organism 

 is rose red diffused through the c}'topla.sm. This is strongest in the epieone and near the 

 periphery, with more neutral pearl-grey tone in the liypocone. In the antapical region the 

 coloring matter or pigment is condensed into a few, very small, rose-red granules. A group of 

 larger granules of the same color can be found in the apex. No striae or other surface markings 

 could be detected. 



DiMENSioxs. — Length, 68-85/*; transdiameter, 54-69/*; axis of nucleus, 

 20-27/*. 



OccuEREXCE. — Tliis was first mot with July 18, 1917, in a haul taken with a 

 iSTo. 25 silk net, 4 miles off La Jolla, California, from 80 meters to the surface 

 and in a surface temperature of 20-8 C. It was found in most of the hauls 

 taken between that date and August 21, both in the surface hauls at the end of 

 the pier at the Biological Station and in those made farther offshore. It was 

 most abimdant towards the end of that time, sixteen individuals being coimted 

 in the last haul examined. 



CoMPAKisONS. — This species belongs to a color group which has represent- 

 atives also in Gyrodininm, CocModininm, Pouchetia. and Eri/tJiropsis, charac- 

 terized by various shades of red. This group is represented in Gjiwiwdininm 

 by G. sulcatum, G. ruhrum, and G. contract uiii, all of which show the same shade 

 of rose red. This is rej)eated also in CocModinium rosaceum. In Gyrodiniiim 



