502 PROCEEDINGS OP THE ACADEMY OF [Nov., 



two deep yellow acicula, the ends of which are exposed as in certain 

 species of Drilonereis and Aracoda. The dorsalmost (fig. 5, a) is much 

 the stouter and the end is blunt ; the more ventral (fig. 5, b), besides 

 being more slender, is prolonged into an acute spinous process, which is 

 frequently broken off. Further caudad the larger aciculum becomes 

 still stouter and more distinctly curved. Two or three very fine 

 acicula reach to the base of the notopodial tubercle (fig. 4). 



On the first somite the setse are all in a small, nearly vertical fascicle 

 between the two lobes, but they quickly rotate to a more oblique 

 position and divide into an oblique supra-acicular group and a horizon- 

 tal subacicular group. The former usually contains two pairs of 

 doubly curved, very acute, limbate setse with strongly striated stems 

 and finely denticulated margins (fig. 6) ; these are turned with profile 

 dorsal and ventral. Subacicular setse are two or three in a horizontal 

 row, turned so that in preparations of the parapodia both blades come 

 into view symmetrically; the blades are shorter and the tips more pro- 

 longed than on the supra-acicular setse (fig. 7). Dorsal setse yellow, 

 ventral nearly colorless. 



Mandibles (fig. 2) brown, with exposed tips white. The two halves 

 merely touch without uniting and then diverge both distally and proxi- 

 mally; dentinal plate not clearly differentiated from the carrier and 

 nearly equal to it in length; the former curved, divergent, ending in a 

 blunt white tip, without marginal teeth; the latter relatively short, 

 broad at distal, tapering to proximal end, divergent. Maxillse (fig. 1) 

 brown, four pairs, all but the first pair (forcep jaws) alternating in posi- 

 tion and more or less asymmetrical. Carriers of forceps filiform, about 

 twice the length of the series of jaws; the two halves coalesced near the 

 end, thickened, then constricted and again enlarged at the distal end ; 

 the forceps roughly triangular, with three stout, hooked teeth along the 

 medial margin of the basal half and the ends strongly hooked. The 

 first accessory plate on the left side longer than the forceps plate, with a 

 large hooked distal tooth and seven stout teeth gradually becoming 

 smaller toward the proximal end , All of the remaining j aw plates differ 

 little in size, but become successively somewhat smaller toward the 

 anterior end; each is supported by two broad divergent wings and the 

 dentinal ridge bears 4-6 conspicuous, slender, claw-like teeth, one or 

 two of the anterior usually being enlarged. 



Color of preserved specimen: anterior end and parapodia rich yellow, 

 pale farther back ; the cuticle only slightly iridescent. 



The type and only known specimen (A. N. S. No. 2313) was found 

 among a lot of Ninoe nigripes Verrill dredged on the muddy bottom of 

 the middle of Buzzard's Bay, Mass., the exact spot being unknown. 



