16G PEOCEEDIXGS OF UNITED STATES NATIONAL MUSEUM. 



ANNELIDA. 



Sthenelais gracilis, sp. nov. 



A small, slender, delicate species. Scales "white, smooth, outer edge 

 with few (12-16) very small, unequal, tapering papillae, which are not 

 crowded, the longest about as long as the intervening spaces. Head 

 short, broad, the posterior and lateral margins rounded, the front emar- 

 ginate. Eyes black, conspicuous ; the i)osterior pair on the dorsal sur- 

 face in advance of the middle of the head ; anterior ijair nearer together, 

 close to the anterior margin ; median antenna long, stout at base, tapering 

 to a slender tip ; the j)alpi have about the same form and length as the 

 median antenna. Dorsal sette longer than the ventral, extremely slender, 

 tapering gradually toward the very fine tips, and very minutelj^ serrulate. 

 Upper ventral setre (2-4) simple, very slender, with the shaft smooth, the 

 serrate i)ortion broader, with rather long ascending spinules, the tips 

 tapering to a long fine point; the median setai, above the acicula, have 

 longer, much stouter, smooth shafts, exi)anded distally, with the terminal 

 portion long, curved, divided into eight to twelve imperfect joints, taper- 

 ing to very slender capillary tips, which are mostly acute, sometimes 

 faintly hooked. Below the acicula there are others, similar in structure, 

 but with the shaft not so stout, and with the terminal i)iece shorter, with 

 fewer joints ; the lower portion of the fascicle consists of numerous, 

 much more slender, capillary setts, with smooth shafts and very long, 

 slender, tapering, terminal pieces, composed of ten to twelve or more 

 imperfect joints. 



Harbor of Gloucester, Mass., 7 to 10 fathoms, sand, 1879 (U. S. Fish 

 Commission). Described from alcohoHc specimens. 



sthenelais Emertoni, sp. uov. 



A small, slender species, with white, translucent scales, their outer 

 edge with very small, nearly equal, slender papillae, often slightly 

 clavate at tip, and rather near together, their interspaces being mostly 

 less than their length 5 surface partially covered Vvith minute rounded 

 verrucce. 



Dorsal setae very slender, capillary, very minutely transversely serru- 

 late. Few (about 4) upper ventral setae, simple, long, slender, with the 

 terminal portion sharply serrulate, the tips fine and sharp; next to 

 these are some slender compound setae, the terminal i^iece slender, 

 straight, of moderate length, acute, with six to eight imperfect joints ; 

 the median setae have much stouter, smooth shafts, expanded distally, 

 and a nearly straight, short, rapidly tapering, sharply pointed, terminal 

 piece, of four to six joints ; below these are some with similar though 

 smaller shafts, and a short, stout, terminal piece, hooked at the tip, and 

 with a sharp ascending spine at about the distal third ; others of the 

 same size have the terminal piece very acute, with six to eight or 

 more joints ; the lowest are very slender, with a longer, very fine, taper- 

 ing, terminal piece, imperfectly divided mto about four to six joints, at 

 each of which there is a projecting acute augle like a tooth; the last of 



