coe: nemerteans of west and northwest coasts. 179 



separated by a conspicuous sphincter of contractile tissue. The 

 position of this sphincter is at about two fifths the distance from 

 snout to intestinal region, and is in the immediate vicinity of the 

 efferent nephridial ducts. The change from stomach to intestine 

 is gradual, and the true intestinal pouches do not begin until after 

 the appearance of a number of shallow pouches in the walls of the 

 stomach. 



Nephridia are very limited in extent, being confined to posterior 

 half of esophageal region proper. The single pair of nephridio- 

 pores is situated at posterior end of nephridial system. Proboscis 

 sheath vessel leaves rhyncliocoel at the same place. Here, too, the 

 esophageal lacunae unite into a pair of ventro-lateral vessels which 

 pass back through the stomach region, and into which the lateral 

 vessels empty at the beginning of the intestinal region. 



Other details of anatomical pecuUarities may be found in the 

 paper cited. 



Habitat. — San Pedro, California, among hold-fasts of kelp and 

 other algae on rocks at low water; not common. 



'24. Micrura verrilli Coe. 



Proc. Wash. Acad. Sci., 3, p. 68, PI. 5, figs. 1-3, 1901 ; Harriman 

 Alaska Expedition, 11, p. 68, 1904. 



PI. 3, figs. .84, 35. 



Body of moderate proportions, but compact and well rounded 

 throughout, flattened only on ventral surface ; head narrow, cephalic 

 furrows rather long ; no ocelli ; mouth small ; caudal cirrus whitish 

 and slender; intestine opens posteriorly above the base of caudal 

 cirrus. Length varies from 5 to 50 cm., more commonly 12 to 

 20 cm. ; width 3-6 mm. 



Color. — One of the most handsomely colored of all species of 

 nemerteans; general color of body pure ivory white with a series 

 of sharply defined rectangular markings of deep purple or wine 

 color covering the greater portion of the dorsal surface (PI. 3, 

 figs. 34, 35). These rectangular markings are surrounded by the 

 white of body, and are sei)arated from each other by very narrow, 

 but sharply defined, white hues. They may be nearly as wide as 



