1911.] NATURAL SCIENCES OF PHILADELPHIA. 267 



Peristomium narrow, continuing outline of prostomium in a regular 

 dome-like curve, but separated by a well-defined dorsal furrow. It is 

 produced somewhat forward to embrace the .prostomium at the sides 

 and dorsally slightly overlaps it as a low, somewhat convex nuchal 

 collar. Ventrally it is cut almost to the posterior furrow by the large 

 mouth, which is partly covered by a broad lip with laterally produced 

 angles. Nuchal cirri slender, tapered, simple, rising high up at the 

 level of the inner lateral tentacles from the extreme anterior margin 

 of the prostomium and separated by one-half their length. They 

 reach to the caudal border of II or well beyond the anterior border of 

 the prostomium. 



Anterior metastomial region slender and nearly terete, the first five 

 podous segments of nearly equal length and width, the ratio being 

 about as two to two and one-half, the greatest width being at the 

 anterior end where the parapodia arise. After VII the segments, 

 become gradually wider and rather abruptly shorter until by XX they 

 are about five times as wide as long and distinctly depressed with the 

 dorsum flattened. This depressed form continues throughout the 

 middle and posterior region. Furrows generally rather weakly de- 

 veloped except between the parapodia. Integuments rather soft, 

 semitranslucent and grayish except in the subparapodial region, where 

 there are thick, opake, whitish glandular areas; surface very smooth 

 with highly iridescent cuticle. Pygidium unknown. 



Parapodia of anterior end prominent, beginning on II near the 

 ventral level and gradually shifting dorsad until by XV they have 

 attained nearly the dorsal level. Anterior parapodia (PI. XVII, 

 figs. 69 and 70) are remarkable for the great length of their parts. 

 The first is situated at the extreme anterior end of somite II and is 

 directed only slightly forward. Succeeding ones shift to a more caudal 

 position and lose the forward slope until the sixth is on the middle of 

 its segment and the third is directed straight laterad. They have a 

 rather long pedicle bearing a notocirrus, neurocirrus and slender 

 neuropodial setigerous lobe divided at the distal end into a scarcely 

 perceptible presetal lip and a remarkably prolonged, attenuate cirri- 

 form postsetal lip. Neurocirrus arises near the base of the ventral 

 surface and is of similar form and nearly equal length to the postsetal 

 cirrus. Notocirrus arises dorsally nearly opposite to the neurocirrus 

 from a thickened notopodial pedicle, into which the acicula enter, 

 followed by a constriction and again by a swelling tapering into a long- 

 slender style one and one-half to twice the length of the neurocirrus, 

 and the longest exceeding the diameter of the anterior segments. 



