COE 



situated latero-ventrally beneath the stomach. At the beginning of the 

 intestinal region the lateral lacunae pass ventrally to join the ventral 

 vessels, which continue to posterior end of body. The rhynchocoel 

 vessel passes beneath the proboscis sheath at the beginning of the intes- 

 tinal region. 



The nephridia are limited to about the middle half of the very short 

 region of the esophagus proper, and are consequently much less ex- 

 tensive than usual. The main longitudinal canal on each side lies on 

 the lateral wall of the lateral blood lacuna and sends branches among 

 the esophageal lacunae. A single pair of efferent ducts pass to the ex- 

 terior above the lateral nerves as usual. In one individual, one of the 

 efferent ducts was peculiar in that it branched just outside the circular 

 muscular layer. Only one of its branches passed to the exterior while 

 the other penetrated only about two-fifths the distance through the 

 outer longitudinal muscular layer. 



Nervous System and Sense Organs. The species is remarkable 

 in having many of the smaller nerves far more conspicuous than in 

 most other species. The cephalic nerves, for instance, are unusually 

 large and numerous. Esophageal nerves are also large, with a distinct 

 commissure near their point of origin from the ventral brain lobes. 

 These nerves join in a distinct plexus beneath the esophagus a short 

 distance behind the mouth. The dorso-median nerve is clearly marked 

 and of remarkably large size. The internal dorso-median nerve, 

 found in many species directly beneath the former and internal to the 

 circular muscular layer, is likewise well developed in this species. 



The brain is massive. The cerebral sense organs are correspond- 

 ingly voluminous, and as usual are bathed posteriorly in the large lateral 

 blood lacunas. The cephalic furrows are of moderate depth, and their 

 lining of regularly arranged epithelial cells with long cilia furnishes 

 strong evidence of their sensory functions. 



Reproductive Organs. Sexual products are fully mature in 

 August. 



Habitat. One specimen measuring nearly half a meter in length 

 was found by Miss Robertson, of the University of California, in the 

 crevices of a rock at Dead Man's Island, San Pedro, Calif. Other speci- 

 mens of much smaller size were found among worm tubes and under 

 stones in the same locality. The species is rather common in mud 

 among tunicates growing on the piles of wharves in San Pedro Harbor, 

 where the worms are usually from 15 mm. to 15 cm. in length. 

 Dredged in several localities off San Pedro in 2 to 20 fms. 



