158 COB 



less than half as great in diameter as are the lateral nerves, close beside 

 which they lie. Quite anteriorly they are situated above the nerves, 

 then gradually assume positions immediately internal to them, and farther 

 back, and after increasing somewhat in size, come to lie beneath, as well 

 as internal to, the nerves. At a point about one-fourth the distance from 

 the brain to the most anterior sexual glands the caeca of the two sides 

 join to form a single broad chamber beneath the esophagus. This 

 is provided with a few broad lateral pockets, which are but slightly 

 differentiated from the main chamber. At about two-thirds the dis- 

 tance from the brain to the most anterior sexual glands the narrow 

 esophagus empties through the dorsal wall of the broad intestinal cham- 

 ber, which shows but slightly developed lateral pouches in front of the 

 anterior sexual glands, although they are well developed farther back. 



The anterior portion of the esophagus is lined with highly columnar 

 ciliated cells, closely packed together with massive gland cells. These 

 latter gradually disappear more posteriorly until there is only a single 

 layer of short cells filled with a clear cytoplasm and provided with 

 long cilia, which line the narrow posterior portion of the esophagus 

 or the ' pylorus' as it is called by Burger. 



Nephridial and Blood Systems. The nephridia are remarkably 

 limited in extent, but consist of unusually large tubules. They are 

 situated above the lateral nerves, beside the esophagus, and immedi- 

 ately behind the brain. Two large canals often occur on each side, 

 one of which lies above and the other below the slender intestinal 

 caecum. After a very short extent, they unite to form a remarkably 

 large efferent duct on each side, which passes above the lateral nerves 

 to open on, or immediately below, the lateral margin of the body as 

 usual. In no other species of Nemertean have the efferent ducts been 

 found to be of such great volume as compared with the size of the body. 



The blood vessels show no remarkable deviations from those in 

 related species. Many of the larger vessels are filled with large, oval 

 corpuscles, with very distinct nuclei. 



Sense Organs. The cerebral sense organs are voluminous and 

 highly specialized. They are situated immediately in front of the 

 brain. The large duct with which each communicates with the exter- 

 ior passes anteriorly to the ventro -lateral margin of the head as usual. 

 The brain shows a correspondingly high degree of development, being 

 remarkably large for the size of the body. 



Reproductive Organs. Sexual products are mature in August. 



Habitat. San Pedro Harbor, Calif., on piles of wharf; off San 

 Pedro, in 3-6 fms. on hold-fasts of kelp ; not very common. 



