ALASKA NEMERTEANS 49 



state of contraction. A V-shaped furrow is present on each side of 

 the head near the tip ; the angles of these furrows point obliquely 

 forward above and below. 



Color. Dull white or pale yellowish on dorsal surface; very 

 thickly mottled with confluent dark brown blotches and dots which 

 largely obscure the ground color. Margins of the head without spots. 

 There are faint indications of a pair of transverse 

 lines without color one near the tip of the snout 

 and the other near the brain region, the latter some- 

 times becoming a shallow, irregular, V-shaped fur- 

 row. Ventral surface dull white or yellowish, 

 without markings other than deeper yellow spots 

 which indicate the positions of the genital sacs, FlG I2 

 and the darker color of the intestinal canal. rus nebulosus. Out- 



Ocelli. On each side of the head are from 18 Hne of the head to 

 to 25 ocelli, arranged in three irregular groups show arrangement of 

 (fig. 12). Close to the anterior border of the ^f ' x D r8al 8m " 

 snout are 4 or 5 large cup-shaped ocelli on each 

 side. Behind these and bordering each lateral margin are about 8 

 much smaller eyes in an irregular group, while 3 or 4 small eyes are 

 scattered between these and the anterior group. Behind each lateral 

 group, and not far in front of the brain, about 7 to 10 small ocelli lie 

 in an irregular cluster deeper in the substance of the head, and are 

 therefore less easily visible. 



Size. The specimens obtained measured 100 to 150 mm. in length, 

 and 5 mm. in width. The esophagal region is short, rounded above, 

 flattened below, and thicker than the intestinal region. 



Proboscis. The proboscis sheath reaches nearly to the extreme end 

 of the body. Proboscis thick, fairly large, and white. It is provided 

 with 17 nerves. Basis of central stylet very much broadened poste- 

 riorly (pi. VIH, fig. 6), flat or even emarginate behind, narrow in front. 

 Central stylet as long as the basis, slender, acutely pointed. Accessory 

 stylets in two pouches ; similar to central stylet, but sometimes very 

 slightly curved ; commonly 3 in each pouch. The pouches lie well 

 behind the central stylet in ordinary extension (pi. vin, fig. 6) . Wreath 

 of gland-cells surrounding basis of central stylet moderately broad. 



In the brain region (pi. xi, fig. i) and for some distance posteriorly 

 an abundance of large multicellular glands are thickly placed in the 

 ventro-lateral aspects of the body, and are mostly situated among the 

 fibers of the longitudinal muscular layer. Behind the brain these sub- 

 muscular glands become so closely packed together that the muscular 



