ALASKA NEMERTEANS 71 



of a dusky gray color above, with narrow, colorless, transverse lines, 

 and with a flesh-colored subtruncate head, much narrower than the body. 

 The same author describes a somewhat similar species ( C. bellus = 

 Micrura belld) from Yezo Island, Japan. This had 10 bluish- 

 white, narrow transverse lines across the ashy-gray dorsal surface, and 

 a white ventral surface. The head was short, and of a vermilion color. 

 Both these species should be referred to the genus Micrura as here 

 defined. 



Habitat. — This species was found only at Virgin Bay, in Prince 

 William Sound. Here it was not uncommon under stones at low 

 water, and was frequently met with in the parchment like tubes of 

 Carinella capistrata^ with which it was associated. 



26. MICRURA ALASKENSIS sp. nov. 

 p1. IV, fig. 2 ; pi. XIII, fig. I. 



Body long and slender, rounded in esophagal region, flattened 

 throughout the whole intestinal region. Head remarkably slender, 

 elongated, and sharply pointed ; cephalic furrows correspondingly 

 long, but their anterior ends do not reach the proboscis pore. Mouth 

 small, and well back from tip of snout ; its anterior end reaches about 

 as far forward as posterior ends of cephalic furrows. 



No ocelli are present. The brain is reddish in color, and shows 

 conspicuously through the tissues external to it. 



The esophagal region is well rounded, and narrower than the suc- 

 ceeding portion of the body. The intestinal region is much flattened 

 both above and below ; its lateral margins are rounded, however. 

 After preservation in alcohol the intestinal region is flattened or even 

 hollowed ventrally, while the dorsal surface is very convex. Posteri- 

 orly the body tapers gradually, and at its pointed extremity an unusu- 

 ally long caudal cirrus is present. This is quite colorless, and contracts 

 after preservation to but a fraction of its original size and length. 



Color. — Two color varieties were met with. Most commonly the 

 general color was a salmon or flesh-color. The esophagal region was 

 pale salmon with tinges of brighter red, becoming lighter anteriorly ; 

 the head pale or nearly colorless ; the brain region distinctly red ; the 

 intestinal region pale salmon, with much more deeply colored intestinal 

 lobes. Running the whole length of the ventral side of the body — 

 from near the mouth to the caudal cirrus — is a characteristic, narrow, 

 cream or flesh-colored stripe in the median line. This stripe is con- 

 spicuous only in the intestinal region, though it may be traced forward 

 to the mouth, as stated. In alcoholic specimens it can still be detected 



