430 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. [1885. 



more marked constriction. The post-buccal segment is longer and 

 somewhat broader than those which sncceed it; its breadth on the ven- 

 tral surface is more marked than on the dorsal, the sides are swollen 

 and extend forward to the parapodia, which are very large and conspic- 

 uously directed forward and downward so as to have a somewhat claw- 

 like appearance; the dorsal margin of this segment is nearly transverse, 

 but often has a slight median lobe ; the outline on the ventral side is 

 deeply concave. The next segment and its appendages are also larger 

 than those which follow, but not so conspicuously diflerent as the post- 

 buccal ; its parapodia are large and project forward, but not so strongly 

 as the preceding ones ; dorsally it does not differ much from those which 

 follow, but on the ventral side it is somewhat longer and is only par- 

 tially crossed by the ventral groove. The next two or three segments 

 show a transition to the ordinary segments of the anterior region, the 

 parapodia becoming less prominent and less turned forward, while the 

 ventral cirrus becomes gradually reduced in length. The buccal seg- 

 ment is narrower and shorter than tiie post-buccal, and bears no ap- 

 pendages. 



The cephalic lobe is short, narrower than the buccal segment, and 

 bears five long, slender, tapering antenni©, which are arranged nearly 

 in a transverse line; of these the three upper are nearly equal in length, 

 while the lateral ones are about one- third the length of the others; all 

 have large, conspicuous, basal articles, which are crossed by about 

 three conspicuous annulations. The two frontal antennae are in the 

 form of small, short, rounded, obtuse verrucse, standing out close to- 

 gether from the anterior margin of the head. The palpi are more than 

 twice as large as the frontal antennce, and situated just below ; they are 

 short, thick, rounded verrucse in contact at their bases, directed forward 

 and downward in front of the mouth. No eyes are distinctly visible 

 in preserved specimens, although there are irregular patches of black 

 pigment around the bases of the antennse. . In the preserved speci- 

 mens two hard, white, acute maxillary plates are usually protruded just 

 below the wrinkled and papillose lower lip, which surrounds them on 

 the lower side like a collar. The parapodia of the post-buccal segment 

 are large, conical, with swollen bases turned forward and downward and 

 strongly transversely wrinkled or annulated around the base; they 

 bear a slender, tapering dorsal cirrus about the middle of the upper side, 

 and a similar, somewhat shorter, ventral cirrus close to the base be- 

 neath ; the setigerous lobe is large, swollen, obtuse, and bilobed at the 

 end, the upper lobe being flat, obtuse, concave beneath, while the lower 

 posterior lobe is in the form of a small conical papilla of equal length close 

 to the tip ; the setae are amber-colored, usually about three in number, 

 large, stout, spine-like, and curved somewhat downward toward the 

 tip ; part of these are usually broken or wanting. On the next segment 

 the parapodia are decidedly smaller and less turned forward ; the dorsal 



