1902.] NATURAL SCIENCES OF PHILADELPHIA. 265 



The uotopodium is merely a dorso-anterior lobe supported by a 

 slender aciculum, which lies close to the ueuropodial aciculuni, but 

 terminates far short of it. The large base of the dorsal cirrus, 

 with its double wing-like lobes, further overshadows the uotopodium. 

 The cirrus itself has the usual form and bears numerous slender 

 cilia, which, on the dorsal side, have a length nearly equal to the 

 diameter of the cirrus and about four times that length ventrally. 

 The ventral cirrus is about one-fifth the length of the dorsal. The 

 first ventral cirrus (somite II) is, however, as usual larger and 

 formed like the dorsal cirri; moreover, its ventral surface bears 

 numerous truncate cilia as long as one-half its diameter. 



Although few in number and arranged in only eight very definite 

 rows, the ueuropodial setse, because of their large size and rich 

 golden color, are very conspicuous. They increase in length to the 

 sixth row, but their spinous ends continue to elongate to the most 

 dorsal (8th) row. All are stout and have abruptly enlarged ends 

 (PI. XIII, figs. 17-19) with long, slightly curved, and rather 

 blunt-pointed, smooth tips. The spinous region is remarkably 

 short, particularly on the most ventral setse, which bear only four 

 pairs of coarse teeth and seldom a trace of lateral fringes. The 

 middle setse have six or seven pairs of such spines with short 

 lateral fringes, and the dorsal setse as many as fifteen or twenty 

 rows of spines, of which the basal ones are very fine. The smooth 

 tips of these dorsal setse are relatively and absolutely shorter as well 

 as more slender. 



The notopodial setse (PI. XIII, figs. 14-16) are of a pale hay 

 color and rather lustreless. They are extremely numerous and 

 arranged in many nearly horizontal ranks, from which they spread 

 fan-like in a nearly horizontal plane outward and slightly back- 

 ward, so that these worms present none of that shaggy appearance 

 which characterizes some Polynoidse. These setse are so long, so 

 numerous and keep so well together, that the parapodia are scarcely 

 visible from above. This species is distinguished from other species 

 of the genus by the fact that all of the notopodial setse, without 

 exception, bear long capillary tips. The longer middle and ven- 

 tral setse are spinous for about one-third of their exposed length 

 and become excessively slender toward the gently .curved tip, which 

 bears a smooth, tapering and flexible filament about one-fourth of 

 the length of the spinous portion. The very numerous rows of fine 



