1909.] NATURAL SCIENCES OF PHILADELPHIA. 257 



ing segments, uniannular, strongly convex and elevated above and 

 divided anteriorly into three lobes : a median united with the median 

 prostomial lobe and a prominent lateral pair which embraces the sides 

 of the prostomium as far forward as the tentacles. Nuchal organs 

 between these lobes and the prostomium, deep, quadrate, with fur- 

 rows passing from the angles. Mouth large with deeply furrowed 

 lips, cutting the peristomium nearly to its caudal border. 



Somite II a simple apodous ring one-third as long as the prosto- 

 mium. Succeeding segments podous, but otherwise similar to II. 

 Anteriorly they are one-eighth to one-sixth as long as wide, but become 

 one-fourth to one-third as wide in the middle and posterior region. 

 All perfectly simple with rounded, bulging sides and separated by 

 deep furrows ; a projection below each parapodium, combined with the 

 flattened venter, produces an almost sole-like surface. 



Pygidium an oblique ring with anus directed obliquely dorsad 

 and surrounded by a low welt. Caudal cirri two pairs, behind anus; 

 the more dorsal cylindrical, longer, about equaling diameter of 

 pygidium and formed of four or five articulations ; the more ventral 

 about one-half as long, clavate and formed of two articulations. 



Parapodia arise from a slight depression close to the ventral level 

 of the segments and project prominently directly laterad to a distance 

 of more than one-half width of body. They are uniramal, consisting 

 of a prominent neuropodium, compressed and somewhat expanded 

 distally where it is divided into a broad rounded postsetal lobe, a 

 shorter presetal lobe subdivided into two small secondary lobes and 

 a small subsetal lobe. In different regions the form of these lobes 

 varies somewhat and especially they become more pointed posteriorly. 

 Neurocirri arise from basal half of venter of neuropodium, and as a 

 simple conical or subcylindrical process reach nearly as far as its end. 

 Notocirri arise in contact with dorsal base of neuropodium and consist 

 of a long cylindrical cirrophore ciliated on its ventral side, probably 

 representing the notopodium, as it contains a slender aciculum or 

 rarely two acicula, and reaching beyond the end of the neuropodium 

 except on anterior segments; at its end it bears a conical style about 

 one-third its length. The first parapodium (on III) differs from all of 

 the others in its very small size, greater simplicity (being entire dis- 

 tally), in its short, rounded neurocirrus and especially in the total 

 absence of a notocirrus. 



Neuropodial aciculum always single, moderately stout, tapered, 

 straight, with a simple blunt point. Notopodial acicula, one, or 



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