46 COE 



tean. Of the Alaska Metanemerteans here recorded this is the only 

 one in which the cerebral sense organs lie posterior to the brain com- 

 missures. The canal by which each sense organ communicates with 

 the exterior is of large size, runs anteriorly in front of the brain, and 

 opens on the ventro-lateral aspect of the head. 



Nephridia. The nephridia reach forward close to the posterior ends 

 of the cerebral sense organs. Anteriorly there is a tangle of small 

 vessels, but farther back these unite into a single large, branched 

 canal which runs close beside the blood vessels above the lateral nerve 

 on each side. From these canals a pair of large efferent ducts pass 

 above the lateral nerve cord, and open to the exterior of the body just 

 below the lateral margin. 



Sub-muscular glands. Present along anterior portion of esophagal 

 region, but not very abundant. 



A broad and profusely branched intestinal ccecum runs forward 

 from the intestine well toward the brain region. The caecum lies well 

 beneath the esophagus and sends off numerous pouch-like branches 

 dorsally above the lateral nerve cords. 



Reproductive glands. These occur both above and below the intes- 

 tinal canal. Although the sexual products were very immature in one 

 of the specimens sectioned, yet the efferent ducts of the glands were 

 formed as far outward as the basement layer of the cutis. Here each 

 duct ended in a swollen chamber lined with cylindrical epithelial cells. 



Size. The individuals of this species varied from 40 to 150 mm. in 

 length. The largest were about 6 mm. wide and 2 mm. thick. 



Habitat. The species was collected at Victoria, B. C., on the 

 piles of the wharf; at Sitka among hydroids, etc., near low water (W. 

 E. Ritter), and a finely preserved specimen from Puget Sound, State 

 of Washington, was given me by Prof. Trevor Kincaid. 



15. AMPHIPORUS TIGRINUS sp. nov. 

 pi. iv, figs. 5-8; pi. vin, fig. 4; pi. x, figs. 3, 4. 



Body moderately slender, rounded throughout, head not marked off 

 from parts immediately following, rather narrow and pointed in front ; 

 posterior extremity of body narrow. On each side of the head is a 

 shallow, inconspicuous, oblique groove. 



Color. In June, at the time the specimens were collected, the 

 sexual products were fully mature, and the species showed marked 

 sexual color varieties. The prevailing color of the females was yel- 

 lowish orange both above and below, but except in the esophagal re- 

 gion, this color was to a great extent obscured by the dark olive green 



