ALASKA NEMERTEANS 53 



body as in A. exilis. Another specimen had 7 efferent ducts on the 

 left side and 8 on the right. Of those opening on the left side the 

 four anterior ones passed dorsally to the nerve cord and then bent ven- 

 trally to open on the ventro-lateral aspect of the body ; the fifth one 

 opened very near the lateral margin, and the last two opened on the 

 dorso-lateral surface. On the right side the four anterior ducts opened 

 ventro-laterally, and the four posterior ones opened on the dorso-lateral 

 surface. The nephridia extend backward beyond the first few pairs 

 of reproductive glands. Here, then, we find the connecting links be- 

 tween the typical Amphiporus nephridium (which passes above arid 

 external to the lateral nerve and then bends downward to open on the 

 ventro-lateral aspect of the body), and the type of nephridium which 

 is characteristic of A., exilis and the Heteronemerteans, and which 

 opens directly on the dorso-lateral aspect of the body. 



Sub-muscular glands are closely packed together in front of the 

 brain and in the brain region. They are not found farther posteriorly, 

 and in this respect the species differs markedly from A. exilis. 



The intestinal ccecum reaches forward well toward the anterior end 

 of the esophagal region. The main caecal cavity, which lies directly 

 beneath the esophagus, sends off numerous lateral pouches above the 

 lateral nerves, and at its anterior end branches into lateral diver- 

 ticula which extend forward on each side as far as the brain re- 

 gion. 



Reproductive glands. The genital products mature in June in the 

 region of Victoria, B. C. The ova develop in sacs which are regu- 

 larly arranged, and extend from the posterior third of the esophagal 

 region to the posterior end of the body. The ovaries, in all cases 

 noticed, were situated immediately above the lateral nerves. In the 

 intestinal region they alternate with the intestinal lobes with a great 

 deal of regularity. Their efferent ducts occupy positions on the latero- 

 dorsal aspects of the body exactly corresponding to those of the poste- 

 rior efferent nephridial ducts. The ducts from the ovaries, however, 

 pierced only the longitudinal muscular layer, and did not penetrate the 

 circular muscular layer of the body wall. These rudimentary genital 

 ducts are further distinguished from the nephridial ducts by lacking a 

 conspicuous epithelial lining. 



Habitat. These slender whitish worms were found in great abun- 

 dance beneath barnacles and other growths on the piles of the wharf 

 at Victoria, B. C. They were found less abundantly under stones be- 

 tween tides at New Metlakahtla and in Glacier Bay, but were not 

 noticed farther northwest. 



