ALASKA NEMERTEANS 47 



color of the mature ova. These ova developed in large pouches on 

 each side of the body, and each pouch with its contents appeared as a 

 dark green spot. In many cases several adjacent pouches lie nearly 

 in contact, giving the external appearance of dark green blotches. 

 Seen directly from the dorsal surface the green spots appear on 

 each side in more or less regular pairs, those of the two sides being 

 separated by an interrupted, narrow, longitudinal, median band of 

 yellow. From the sides the ovaries appear as irregular transverse 

 stripes of dark green alternating with the yellow color of the body — 

 hence the specific name, tigrinus. The males are much less deeply 

 colored. They are pale yellowish with a slight tinge of green, and 

 the spermaries appear as innumerable cream-colored specks. Both 

 males and females have a narrow, longitudinal, median band of brown- 

 ish on the anterior dorsal portion of the body. After preservation in 

 alcohol both sexes assume a greenish color, which is retained even after 

 mounting in balsam. 



Ocelli. — The eyes are numerous, and are arranged in two irregular, 

 and scarcely separated, clusters on each side of the head in front of 

 the brain. The individual ocelli are so irregular in shape, so variable 

 in size, and so closely massed together, that it is difficult to determine 

 their precise number. Many of them appear as ragged pigment 

 masses. Commonly, however, there are a dozen or more of such 

 ocelli in each of the anterior clusters, and perhaps 8 to lo in each of 

 the posterior ones. The ocelli of the anterior clusters are scattered 

 through the tissues of the head from the dorsal to the ventral surface. 

 Some of the ocelli are three times as large as are others. In contraction all 

 the eyes of the same side form a single confused cluster. Because of 

 their variability of position no drawing is given of their arrangement. 

 Proboscis. — The long and well developed proboscis is provided 

 with a remarkably weak armature. This consists of a small central 

 stylet and two pouches of accessory stylets. The central stylet is 

 small and short, but is acutely pointed. Its massive basis, double the 

 length of the central stylet itself, is short, thickened, and rounded be- 

 hind (pi. viii, fig. 4). In a worm 75 mm. long, the central stylet 

 measured about .075 mm. in length; the basis was .15 mm. long and 

 .071^ mm. in average diameter. The accessory stylets are, like the 

 central stylet, short, broad at the base, but sharply pointed. They 

 usually number about five to each pouch. The glandular wreath 

 about the stylet is well developed, and in the specimens examined is 

 deep green in color even after mounting in balsam. The proboscis 

 sheath reaches nearly to the posterior end of the body. 



