1911.] NATURAL SCIENCES OF PHILADELPHIA. 241 



Proboscis protruded on many specimens to varying degrees and 

 presenting very different aspects. On the type it is a short truncate 

 cylinder 3.5 mm. in diameter and equally long, divided by three 

 furrows into as many zones: first, a soft, somewhat inflated basal 

 zone which, because of the incompleteness of the furrows in a nairow 

 medial dorsal region, here encroaches on the other rings to the end of 

 the proboscis; second, a narrower, firm and muscular middle ring and, 

 third, a still shorter terminal muscular disk of a deep brown color with 

 a central rugous area and a slight vertical furrow dividing it to the 

 margins. On other specimens the basal annulus is much larger and 

 more inflated, the terminal disk is sometimes folded together along 

 the vertical furrow in partial retraction, and sometimes in complete 

 extension has the rugous area protruded as a prominent rounded mass 

 turned toward the dorsum to conceal the mouth from below and 

 marked by a slight median furrow and numerous, slightly sinuous, 

 transverse raised lines. Still other specimens have this distal region 

 much more extended to a length exceeding all the rest of the proboscis, 

 and bearing the large orifice at the end of the flat, smooth and soft 

 dorsal part, the deep spoon-shaped or ventricose sides and venter 

 being completely formed by the rugous area. 



Setae all nearly or quite colorless, tubular, with soft, granular con- 

 tents, very brittle. When massed the setse are sometimes distinctly 

 yellow and those of some of the younger specimens exhibit a beautiful 

 satiny luster. Notopodials in somewhat whorled, suberect tufts, 

 becoming longer and more recumbent toward the caudal end. They 

 are rather stout, slightly curved and tapered to rather blunt points, 

 below which, at a varying distance, is a spur, conspicuous on the more 

 ventral setae (PI. XV, fig. 1) which are truly bifid, nearly obsolete on 

 dorsal setae (PI. XV, fig. 3). Most notosetae of middle segments are 

 smooth or nearly so, but some (fig. 2) exhibit slight serrations, and this 

 may be the normal state of unworn setae. Posteriorly the setae become 

 longer and usually lack the spur; anteriorly contrary changes occur. 

 Neuropodial setae much more numerous, slender and elongated, form- 

 ing very dense tufts which spread laterad, but posteriorly more caudad. 

 Posterior setae are more elongated and truly capillary, but on some 

 examples they exceed the body width, even on the middle parapodia. 

 They are of the same type as the notopodials, but the spur is close to 

 the tip and small or obsolete (PI. XV, figs. 4, 5). Toward the ends 

 of the body modifications similar to those affecting the notosetae 

 occur (PI. XV, fig. 6). 



Color. Probably richly colored in life, but most of the preserved 



