coe: nemerteans of west and northwest coasts. 261 



The subrausciilar glands extend posteriorly but little beyond the 

 brain region, and are always buried more or less deeply in the longi- 

 tudinal muscular layer, never projecting freely into the underly- 

 ing gelatinous tissue of the body cavity. As in other species, the 

 glands are multicellular, a dozen or more nuclei, without definite cell 

 boundaries, being commonly seen in a single section of one of the 

 glands. 



Alimentary canal. — The mouth actually opens into the rhyncho- 

 daeum, although in the specimen fi'om which the proboscis had been 

 extruded the mouth opening was so near the anterior end of the 

 latter as to be almost independent of it. In the region in front of 

 the brain the esophagus is large, and is lined with columnar, ciliated 

 epithelial cells, while the rhynchodaeum is vei-y much smaller and is 

 lined with flattened cells (PI. 19, fig 119). 



The esophagus passes gradually into the stomach, which through- 

 out its length is small in comparison with the diameter of the body. 

 It lies near the ventral wall of the body, and is widely separated 

 from the lateral and dorsal body walls by tlie remarkably volumin- 

 ous gelatinous tissue described above (PI. 19, fig. 120). 



The intestine exhibits the usual paired lateral diverticula, but 

 these do not reach nearly to the body walls ; everywdiere they are 

 surrounded by a very thick layer of this gelatinous tissue (PL 20, fig. 

 122), which is scarcely less voluminous here than in the esophageal 

 region. 



The intestinal caeca are but slightly developed. The pylorus is 

 short, and at its opening into the dorsal wall of the intestine a broad 

 intestinal caeciim passes forward beneath the stomach. This does not 

 extend far anteriorly, however, but soon breaks up into secondary 

 branches of small size which lie beside the stomach (PI, 19, fig. 120) . 

 These branches reach anteriorly only about as far as the posterior 

 efferent nephridial ducts which are situated far behind the brain. 



Nephridia. — The nejihridial tubules extend forward about as far 

 as the middle of the brain lobes. Posterior to the brain a multitude 

 of fine canals ramify through the parenchyma of the body cavity". 

 They lie mainly above the lateral nerves and penetrate the gelati- 

 nous tissue in all directions, extending from the muscular layers of 

 the body walls inward to the stomach and proboscis sheath (PI. 

 19, fig. 1*20). 



The nephridia extend throughout the whole length of the eso- 



