378 PROCEEDINGS OF THE ACADEMY OF [April, 



and hatchet-shaped with the crest-like border divided into six to eight 

 short, bhuit processes sometimes flattened or even bifid (Pi. XXXII, 

 fig. 77). 



Parapodia prominent, tlie neuropodia of typical segments about 

 one-third width of segments, pointing straight laterad, stout, conical, 

 little tapered, truncate distally and stepped for the usual three series 

 of setae. Integument much wrinkled and studded on the sides and 

 venter with spherical papillae much more widely separated than those 

 of A. castanea and smaller than those of A. armifera, but larger and 

 more crowded at the bases of the setae. The aciculum projects slightly 

 from the dorsal step of the foot. Notopodium a low nub extended to 

 the dorsal surface. Neurocirrus arises postero-ventrally from a low 

 fold or ridge in place of a distinct ceratophore near middle of neuro- 

 podium; style acuminate, rather stout in basal half, slender and 

 tapered distally and terminated by a scarcely evident knob, smooth, 

 not quite reaching base of middle series of setae. Notocirri spring 

 from stout cirrophores behind the lateral tuft of notopodial spines; 

 styles slender throughout and little tapered, a slight subterminal and 

 a scarcely evident terminal enlargement. They perforate the felt 

 and rise above it along with the lateral tufts of notopodial spines. 

 Anteriorly the parapodia are gradually reduced in size and directed 

 more and more forward, the first or peristomial being alluded to above. 

 Neurocirrus of II somewhat longer than the others and arising nearer 

 to the base of the foot which approximates the form of the first. 

 Posteriorly the parapodia become very small but slender and elongated 

 with the notopodium as well as the neuropodium projecting freely. They 

 bend ventrad and toward the middle, converting the venter of this 

 region into a groove closed posteriorly. The neurocirri become 

 relatively longer and the subterminal and terminal enlargements are 

 exaggerated. 



Dorsal felt an even, regular and near smooth investature covered 

 with a coating of mucous, silt and foreign particles of various kinds. 

 It is unusually thick and composed of very fine fibers arranged in two 

 layers, the inner thin, membrane-like and clean, the outer much thicker 

 and carrjdng much foreign matter. Penetrating its lateral parts 

 along the sides of the worm are the stout, brown, notopodial setae in 

 two series and below these the beautiful flowing plumes — imusually 

 long and abundant — of iridescent setae which glow with a fine golden- 

 green or in some lights, a blue-green metalic luster. Many of these 

 fibers curve upwards onto the felt, the fibers of which also are slightly 

 iridescent when clean. 



