^6 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. 



Nefhridia. — 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 ccecu?n runs forward 

 from the intestine well toward the brain region. The cascum 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 outv^ard 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; p1. VIII, 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 



