710 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [12] 



A short conical cirrus, arising from the lower face of the palpi at about 

 the middle point, extends directly downward. This is a peculiar feat- 

 ure, which seems not to have been previously described in any species 

 of this family. The antennae are claviform; the median longest, about 

 twice the length of the head and palpi together, arising between the 

 posterior eyes ; the lateral antennse arise very near the anterior margin 

 of the head, just outside of the anterior eyes; they are about two-thirds 

 as long as the median. 



The tentacular cirri, in all respects similar to the lateral antennae, 

 arise very near the anterior margin of the segment ; the lower cirrus is 

 a little shorter than the upper. 



The buccal segment is as long as the next segment. 



The dorsal cirri of the first two setigerous segments are a little more 

 slender than the tentacular cirri, but in other respects similar to them ; 

 those on the remaining segments are distinctly articulated; they vary 

 in length from two to four times the width of the body. There are three 

 anal cirri, two lateral articulated, a median not articulated. The 

 pharynx reaches to the middle or to the posterior margin of the third 

 segment ; we did not make out clearly the structure of its anterior end. 

 The stomach is a little longer than the pharynx, very large, nearly fill- 

 ing the segments, which it occupies; it has the structure common to 

 this group, but in front shows a peculiar organ, as to the character of 

 which we made no notes in the living specimens, having probably failed 

 to observe it. This organ is transversely oval, convex in front, concave 

 behind, and crossed by numerous waved lines, which radiate from the 

 middle point behind. The feet are very long (fig. IG), and bear a long, 

 <onical, or finger-shaped ventral cirrus, which points either directly or 

 obliquely backward. 



The setae are from five to seven in each foot, and of two kinds : one 

 (fig. 14) compound, with the appendix delicate, elongated ; the other, 

 of which there is but one in each bundle, simple (fig. 15), with a small 

 terminal button. The longest of the compound setae are about as long 

 as the foot, the others from one-half to two-thirds as long. 



The body is much wider in the middle than at either extremity; seg- 

 ments deeply incised, especially along the middle third. Two of the 

 median segments are shown in fig. 13; these are from the same speci- 

 men as fig. 13, and are magnified to the same extent. 



Body slightly convex above, nearly flat below, colorless ; intestine 

 brown, yellowish brown, or reddish brown. 



Dorsal cirri and antennae readily lost. This species throws itself 

 quickly into a coil, very much as is the habit of Glycera {Ehynchobolus). 



Length, 25°^™. 



Greatest width, 0.2"'°^ (about). 



l!^umber of segments, 45. 



Number of segments varies from 35 to 50. 



Low water, sand, Race Run, near Provincetown. 



