476 MEMOIES OF THE UNIVERSITY OF CALIFORNIA 



Tlie sulcus invades the epicone but a short distance beyond the anterior flagellar pore as a 

 shallow trough. Below this point it descends posteriorly as a slender channel in a deep trough, 

 whose borders form high ridges on either side. Beyond the distal junction of the girdle and 

 sulcus it traverses the hypocone but a short distance as a shallow channel. Its total torsion is 

 only 0.3 turn, but the apical section may be incompletely delineated. 



The ocellus is located in the ventral region close to the posterior flagellar pore and to the 

 left of the sulcus. Its length is 0.5 transdiameter and it is directed anteroventrally about 45° 

 from the vertical. The lens is oblong, somewhat elaviform, and is composed of four imequal, 

 hyaline, colorless spheroidal or ellipsoidal moieties, closely pressed together in a linear series 

 decreasing in size towards the melanosome. Its base is imbedded in the amoeboid pigment 

 . mass. The greater part of this is rose red in color, with a smaller mass of black pigment on the 

 ventral side. The central core is red. 



The nucleus is large, ovoidal. and anteriorly placed in the ventral part of the epicone. 

 Chromatin strands follow the course of its major axis. Its major and minor axes are 0.8 and 

 0.4 transdiameter respectively in length. 



A large club-shaped pusule opens anteriorly into its anterior flagellar pore. The posterior 

 one was not observed. The cytoplasm is rather coarsely gi-anular and clear with a few large, 

 bluish vacuoles in the anterior region. Two dark olive buff food bodies were present posteriorly. 

 On the dorsal side of the body, peripherally located, are many rufous colored granules, gathered 

 near the girdle and extending anteriorly in longitudinal rows, about eight in number, in the 

 peripheral plasma to near the apex. Rod-shaped masses of the same rufous material are found 

 along the proximal border of the girdle in the posterior region. On the opposite side from the 

 ocellus are several subparallel rows of granules and several larger spherules of the same rufous 

 material. No surface markings or striations were present. 



The color is a light, dull .vellow mixed with grey and distributed quite uniformly through 

 the cytoplasm. 



The most remarkable organ of this animal is the contractile prod which emerges from the 

 widened sulcus just below the distal end of the girdle and hangs pendant ventroposteriorlj' at 

 about 45° from the horizontal in its basal part, then curves posteriorly. In form it is a curved 

 cone with rounded apex. Its length and basal diameters are 0.50 and 0.24 transdiameter respec- 

 tively and the angle of the core is approximately 25° when the prod is extended. When con- 

 tracted it merges somewhat basally with the ventral face of the hypocone. The recession of the 

 ventral face of the hypocone is apparently correlated with the development of this protrusion 

 and the consequent withdrawal of the material from this region utilized in its formation. The 

 cavity aboiit the base is so slight as not to merit the designation of a recess such as occurs in 

 Ei-ythrops'is. 



DiME>rsiONS. — Length, 10m- ; transdiameter, 49/^ ; axes of nucleus, 29/* and 19;^ ; 

 length of ocellus, 20/* ; length of fully extended prod, 25/*. 



Occurrence. — A single individual was taken July 25, 1917, 11 miles off La 

 Jolla, California, with a No. 25 silk net in a haul from 80 meters to the surface, 

 in a surface temperature of 21-7 C. 



Acti^'itiEkS. — The animal progresses by rotation and circling in anticlockwise 

 spirals several times its length in diameter and when quiescent the prod is seen 

 to xmdergo somewhat spasmodic contractions. They are not repeated as regu- 

 larly and rapidly, nor are its excursions so extended as in Eri/fhropsis. 



CoMPARisoxs. — The median location and the displacement of the girdle are 

 not unlike that seen in Pouchetia striata and P. voracis, and the structure of 

 the ocellus is quite similar to that of P. maculata, although the pigment has less 



