470 MEMOIRS OF THE UNIVERSITY OF CALIFORNIA 



The girdle joins the sulcus at a point distant from the apex 0.4 of the total length of the 

 body. It sweeps around the hotly in a descending left spiral and after 1.5 turns meets the girdle 

 0.2 of the total length of the body from the antapex. It occupies a broad, deep depression with 

 smoothly rounded borders. The anterior flagellar pore is situated at the point of its anterior 

 junction with the sulcus and the posterior pore slightly below the posterior junction on the 

 opposite face of the body from the anterior pore. The transverse tlagellum traverses about 0.5 

 of its length. In figure 118, plate 11, the tlagellum was inverted and occupied the anterior 

 portion of the sulcus. In figure 120 and text figure 00, 1, it is found occupying its normal 

 position on the girdle. 



The sulcus invades the epicone in a wide loop of 1.5 turns above the anterior junction with 

 the girdle. It passes once around the body and then turns upward and abruptly to the left, 

 ending on the apex which it notches. Below the anterior pore it turns in a descending left 

 spiral course, making 0.5 turn before meeting the distal end of the girdle. Beyond this it makes 

 one complete turn around the antapex, ending on the left side. The sulcus occupies a rather 

 broad and deep channel throughout its course except where passing over the ocellus below the 

 anterior pore. Here it becomes somewhat obscured by the projecting body of the pigment mass. 



The ocellus is large and situated immediately below the proximal part of the girdle near the 

 middle of the body and on the left of the sulcus, and is directed dorsoventrally or postero- 

 anteriorly. Its length is 0.42 transdiameter and its axis is subhorizontal, raised 20° above the 

 horizontal and pointed to the left in one specimen (pi. 11. fig. 118) and deflected posteriorly an 

 equal amount or more in a second (moribund) individual. The lens is large, spherical, with 

 concentric laminae of a clear, hyaline material. It is slightly imbedded in the pigment mass. 

 The melanosome is generally larger than the lens, actively amoeboid and black in color with a 

 lighter central core. In figure 118, plate 11, the lighter central core is seen emerging from the 

 black pigment ma.ss as a large clear body just above the mass of pigment which is here rounded 

 up, and pressing close against the lens. In this same figure the line of sulcus across this region 

 is not shown and one small are of the outer wall of the lens is omitted by oversight. In text figure 

 00, 1. the details of this area are complete. In figure 120, plate 11, another individual is shown 

 in which the amoeboid melanosome has moved farther anteriorly around the lens. Since this 

 is seen here from the melanosome end its length is foreshortened and the relations of lens and 

 melanosome somewhat obscured. 



The nucleus is large, spheroidal and is located in the anterior half of the body. About 

 thirty-five fine parallel beaded chromatin threads traverse it obliquely. Its diameter is 0.27 

 transdiameter of the body. A large, bifurcating pusule filled with pinkish fluid passes into the 

 center of the body from the anterior flagellar pore and a smaller sacklike one trends posteriorly 

 from the same region. On one face six to eight nearly equidistant striae, interrupted by the 

 ocellus, are found in the peripheral plasma. 



The cytoplasm is very clear and transparent. A few refractive oil drops and a single large, 

 ochraeeous food mass were found close behind the ocellus in figure 118. A few minute, bluish 

 green oil droplets were scattered through the peripheral pla-sma. The color is a clear, light 

 violet, diffused somewhat uniformly throughout the peripheral zone of cytoplasm. The indi- 

 vidual drawn in figure 120, plate 11, showed the same diffuse distribution of the color as in 

 figure 118 when first observed. After being kept under the cover glass for nearly one hour the 

 color began to condense into small granules and longitudinal lines, especially along the girdle, 

 which formed a mesh over parts of the body, leaving the remamder colorless. These lines of 

 pigment appeared strikingly amoeboid in their movements, changing quite rapidly during the 

 time required for a camera sketch. The same change took place in the first individual before 

 cytolysis occurred. 



Dimensions. — Length, 106-115^' ; transdiameter, 51-63/^; diameter of micleus, 

 16-18^ 



