COE: NEMERTEANS OF WEST AND NOETHWEST COASTS. 151 



lateral nerve cord, and opens to the exterior on the dorso- lateral 

 aspect of the body (PI. 13, fig. 82). 



As stated above, the efferent ducts lie in the same region as the 

 posterior ends of the nephridial glands. Back of this point a cross 

 section nearly always shows two sections of the nephridial canal 

 just ventral to the lateral blood vessel (PI. 14, fig. 8B). One of 

 these sections commonly lies nearer the median line than does the 

 blood vessel, and this represents that portion of the canal which is 

 passing posteriorly, while the other lies a little nearer the lateral 

 margin of the body, and corresponds to the limb of the vessel which 

 is passing forward toward the efferent duct. Both limbs lie just 

 internal to the longitudinal muscular layer, but sometimes (PI. 14, 

 fig. 83) penetrate this layer, and are connected with the outer por- 

 tions of the body walls by strong fibrous bands. 



The efferent ducts, which are narrower than the longitudinal 

 canals, pass just externally to the dorsal pair of lateral blood 

 vessels, and in penetrating the outer circular muscular layer spread 

 out and lose their characteristic lining of columnar epithelium. 



In figure 82, PI. 13, and figure 83, PI. 14, the large efferent duct 

 on the left side opens directly outward, while the small duct beside 

 it, and nearer the median line, runs far backward and then bends, 

 forward to the efferent duct. On the right side the nephridial sys- 

 tem is cut a little more posteriorly. The canal lying in contact with 

 the dorsal lateral vessel is the right efferent duct, which in this 

 instance bends obliquely backward. The nephridial canal lying 

 nearest the lateral nerve is the limb which passes forward to the 

 efferent duct, while the one lying nearer the median line is the limb 

 which runs backward. Occasionally a third canal is cut on one 

 side, and this is where a bend occurs in one of the longitudinal 

 canals. 



JVervous system. — The nervous system is closely similar to that 

 in C. armandi, as described by Burger ('95). The brain is volumi- 

 nous and both commissures ai'e large. 



A pair of large buccal nerves is given off from the internal borders 

 of the ventral ganglia immediately behind the commissures. These 

 nerves lie immediately beneath the ejnthelium of the mouth and 

 anterior portion of the esophagus, as in other genera. 



The large dorsal median nerve extends from the dorsal commis- 

 sure backward into the intestinal region. Anteriorly it lies external 



