ALASKA NEMERTEANS 5 1 



pl. xi, fig. i) which arises from the ventral side of the dorsal ganglion 

 near the ventral commissure. The union of the lateral nerve cords 

 above the anus lies in the same section as the anastomosis of the three 

 longitudinal blood vessels. A pair of small nerves from the lateral 

 cords continues backward beyond the commissure to the end of the 

 body. 



Reproductive organs. The sexual glands first make their appear- 

 ance in the esophagal region at the point where the unpaired intesti- 

 nal caecum receives its pair of anterior branches. Those sexual 

 glands which are situated most anteriorly lie below the alimentary 

 canal, internal to the lateral nerves, and open on the ventral surface of 

 the body. Farther back are commonly four or five reproductive 

 pouches in a single section. These lie mainly below the intestine, 

 but no matter what their position they all open to the surface of the 

 body below the lateral margins. Those lying farthest from the mid- 

 dle line and above the lateral nerves open ventrally between the nerve 

 cords and the lateral margins. Sexual products appear to be fully 

 mature in July. 



Habitat. Beneath stones near low water at Kukak Bay, Alaska 

 Peninsula (T. Kincaid). 



17. AMPHIPORUS LEUCIODUS sp. nov. 



pl. vii, fig. 6. 



Body usually not more than 50 to 75 mm. in length, slender, elon- 

 gated, flattened posteriorly, not capable of great contraction. Head 

 narrower than parts immediately following. An inconspicuous V-- 

 shaped furrow on dorsal surface back of head, seen only under favor- 

 able conditions. 



This species resembles young individuals of A. exilis, with which 

 it is often associated. It is likewise similar in many respects to A. 

 lactijloreus (Johnston) Mclntosh, from which it differs widely in the 

 armature of the proboscis and in many other anatomical features. 



Color. Opaque white, sometimes with a pale reddish or yellowish 

 tinge. This color is commonly uniform throughout, though it is some- 

 what influenced by the internal organs which show through the body 

 walls. The brain is pinkish, the intestine often brownish. 



Ocelli. There are four irregular, but usually distinct groups of 

 minute ocelli on the anterior portion of the head. Bordering each 

 antero-lateral margin of the tip of the snout is an elongated cluster of 

 about 8 to 12 ocelli (fig. 13). Posterior to these marginal clusters, 



