1835.] PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 429 



its short posterior aunulation a pair of slender, tapering tentacular 

 cirri, which are about equal in length to the lateral antennie, and when 

 directed forward their tips extend beyond the bases of the superior 

 antennae. The eyes are small, not conspicuous, and situated between 

 the bases of the two outer antennae. The head in preserved specimens 

 is often concealed as far as the eyes at the bases of the antennae, by 

 being retracted beneath the free anterior edge of the large buccal seg- 

 ment, which is about as long as the four succeeding segments. The 

 branchiae commence on the sixth body-segment and extend to near the 

 posterior end of the body, only about five of the caudal segments being 

 without them. The gills when best developed are pectinate, with about 

 eight long, slender papillae. The i)arapodia of the lirst four or five 

 anterior segments bear a long, slender, tapering, dorsal cirrus; a 

 much shorter, obtuse, papilliform ventral cirrus; and a small, short, 

 round, setigerous lobe. On the sixth and succeeding segments the 

 ventral cirrus becomes a low, rounded or oblong tubercle, surmounted 

 by a minute papilla, but on the posterior segments the ventral cirrus 

 again becomes an elongated, conical, obtuse papilla. The dorsal cirri 

 decrease in length from the second segment backward, but those on the 

 seven anterior segments are distinctly longer than those that succeed 

 them. The setigerous lobe increases in size from the anterior segments 

 backward. The setae on the anterior segments are few and small, but 

 increase in number and size on the succeeding segments. The caudal 

 cirri are moderately long, slender, acute, in length somewhat exceeding 

 the tentacular cirri. 



Stations 865, 871, 872, in 65 to 115 fathoms, 1880; station 950, in 71 

 fathoms, 1881; stations 1092 and 1109, in 202 and 89 fathoms, 1882, 

 and at many other stations in later years, in 60 to 258 fathoms. 



Hyalincecia artifex Verrill. 



Verrill, Proc. U. S. Nat. Mus., vol. iii, p. 358, 1880. 



Verrill, Trans. Conu. Acad., vol. iv, p. 323, pi. 14, tigs. 6-6d ; pi. 17, figs. 14, a, 



h, 14a, 1881. 

 Verrill, Bull. Mus. Comp. Zool., vol. xi, p. 45, pi. 6, figs. 1, 9, /', Kjy h 1883. 

 Verrill, Eeport U. S. Fish Com. [p. 22], pi. 41, figs. 178, a, 6, 178a, 179, a, b, c, 



d, e; pi. 44, fig. 177, 1885. 



Body much elongated, composed of very numerous segments, broad 

 and strongly depressed, except near the anterior end, where the body 

 becomes narrower and thicker to the buccal segment, which is nearly 

 as high as broad. The anterior segments are much longer than those 

 farther back, strongly convex above, and with a broad and deep ventral 

 furrow in the preserved specimens. These segments are widest and 

 somewhat swollen at the front edge, narrowing backward in the middle 

 and posterior regions ; the segments are short and closely crowded, less 

 convex above, nearly flat, and with a shallow groove beneath ; these 

 segments have only a slight constriction between them on the dorsal 

 and ventral surfaces, while those of the anterior region have a much 



