178 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 



23. Micrura nigrirostris Coe. 

 Harriman Alaska Exjjedition, 11, p. 198, PI. 17, figs. 7, 8, 1901. 



PI. 3, fig. 29. 



The individuals of this species are beautifully and strikingly 

 colored, and may be recognized by the following peculiarities : — 



Body of small size, only moderately slender, rounded anteriorly, 

 slightly flattened in intestinal region ; head commonly a little 

 wider than parts immediately following ; tip of snout rather 

 narrow, cephalic slits of moderate length; caudal cirrus was not 

 found in the few individuals examined. 



Ocelli wanting. 



Length of the few individuals found 10-80 ram. ; diameter 

 2-3 mm. 



Color both above and below bright blood red, sometimes with a 

 tinge of purplish. Head blood red in color, with a narrow, but 

 very sharp and conspicuous, transverse band of white on dorsal 

 surface near tip of snout (PI. 3, fig. 29). Immediately in front of 

 this is a narrow, blood red area bounded behind and laterally by 

 the narrow white band, and in the middle of the red area, and 

 situated on the exact tip of snout, is a small, rounded, dark brown 

 or black spot. Color after preservation brownish, the terminal 

 markings being still retained. 



Proboscis has only two muscular layers, the inner longitudinal 

 muscles being completely wanting. Circular muscles of proboscis 

 sheath much thickened immediately in front of intestinal region, 

 representing perhaps an indication of the inner circular muscles 

 which are found in same region in several related species. 



Cephalic glands well developed, extending posteriorly nearly to 

 the brain. 



Cephalic furrovjs are narrow, and are not deep. Except at their 

 posterior ends, they reach less than half the distance from surface 

 to rhynchodaeum or brain. 



Alimentary canal. — The two divisions of the esophagus, 

 described for Linens rubescens, L. flavescens, and other forms, 

 are also well marked in the present species. The change from 

 esophagus proper to stomach is abrupt, and the two sections are 



