1917] Essenherg: New Species of Polynoidae 49 



the tips of the longest setae, covered with short, club-shaped papillae. 

 The ventral cirri are short and fusiform. 



The parapodia (pi. 2, fig. 5) are biramous. Each ramus is sup- 

 ported by an aciculum. The ventral ramus is by far the more promi- 

 nent, forming a triangle and ending in a narrow projection. The 

 dorsal ramus or notopodium is less prominent, ending in a long, 

 finger-like projection, through which the aciculum projects. 



The neurosetae are very numerous, 40 to 50, varying in size and 

 structure. The ventral-most setae (pi. 2, figs. 9 and 10) are the 

 shortest, about one-half the length of the long setae, with less con- 

 spicuous serrations. The setae increase in length and complexity 

 toward the dorsum. The long neurosetae (pi. 2, fig. 11) are slender 

 and the serrations are conspicuous. The ventral setae have a strong 

 subterminal tooth, and curved, pointed tips. The dorsal setae are 

 also very numerous (about 50 or more). In their arrangement they 

 give the appearance of a fan. They are arranged in six or more rows. 

 The ventral setae are the longest, being about three times the length 

 of the long notosetae, decreasing in length dorso-anteriorly. The 

 setae are curved, ending bluntly, their distal ends, except the extreme 

 tips, being covered with fine serrations, which are more pronounced 

 on the convex side. The postero- ventral setae (pi. 2, figs. 6 and 7) 

 are long and stout, about one-half the width of the body. The extreme 

 dorso-anterior notosetae (pi. 2, fig. 8) are very short, strongly curved, 

 with but a few serrations on the convex side. Between these extreme 

 dorsal and ventral setae all gradations of size occur. The color of the 

 setae is golden yellow. Their arrangement is such that in each suc- 

 ceeding row the setae curve in opposite directions. This arrangement 

 may be of some service as a protection for the animal. 



There are fifteen pairs of elytra (pi. 2, figs. 2 and 3) covering the 

 greater part of the dorsum, except the narrow median line, which is 

 partly exposed. They occur on segments 2, 4, 5, and on all alternate 

 segments to 25; then on 26, 29 and 32. The first pair of elytra (pi. 

 2, fig. 2) are nearly orbicular ; the rest are reniform. They are densely 

 covered with brown, spinous protuberances (pi. 2, fig. 4). These pro- 

 tuberances are club-shaped and covered with secondary projections. 

 Numerous soft, white projections are scattered over the elytra. These 

 projections are of the same shape as the marginal fringes, many 

 exceeding the latter in length. The marginal fringes are confined to 

 the postero-lateral margin only. A few large, soft tubercles are found 

 near the lateral margin of the elytra. 



