328 PROCEEDINGS OF THE ACADEMY OF [June, 



posteriorly complete cotype is 18 mm. long, the anterior region being 

 5 mm. and the posterior 5.5 mm. Segments 23 + 26 + 31 = 80. 



Form rather short and stout, widest at the middle, the ventral sur- 

 face flat, the dorsal more or less arched, most so in the anterior region, 

 which is nearly as high as wide; the middle and posterior regions 

 depressed. 



Prostomium small, short, bent downward, subprismatic with 

 rounded angles, about two-thirds as long as wide and deeper than long, 

 the front abruptly vertical, somewhat excavated for the tentacles. 

 Eyes two pairs, moderately large with large lenses, brown, occupying 

 sides of prostomium, the anterior pair directed chiefly forward, the 

 posterior upward. Though themselves distinct they are enveloped 

 in an irregular curved, broad band of black pigment which occupies 

 most of the lateral and posterior dorsal part of the prostomium. The 

 three tentacles arise close together, the median more dorsal, from 

 a depression in the middle of the frontal face, small, slender, unjointed, 

 subequal, somewhat exceeding length of prostomium. Palpi directed 

 ventrad, thick, fleshy separated knobs. 



Peristomium achaetous, largely concealed by prostomium, only a. 

 very short dorsal ring and larger lateral prominences showing. Two 

 pairs of tentacular cirri, unjointed but transversely wrinkled, the 

 ventral about as long as width of prostomium, the dorsal about one 

 and one-half times as long. The nuchal fold arises from the dorsum 

 of II and is a prominent, semicircular, deeply pigmented, free, mem- 

 branous flap, with a basal, width equal to one-half the segment and 

 covering the posterior part of the prostomium as far as the anterior 

 eyes. Somite II and remaining setigerous segments are uniannular 

 and well marked by irregular furrows, differing in the several regions 

 as indicated above. Pygidium a small, low, dome-shaped ring having 

 a pair of short, thick fusiform cirri. 



Parapodia, owing partly to the contraction of the specimens, very 

 little prominent, those of the anterior and posterior regions uniramous 

 (PI. XV, fig. 8), of the middle region biramous (fig. 9). Neuropodia 

 short, stout, with blunt ends, terminating in two short, thick, rounded 

 lips, of which the postsetal is usually slightly the longer; both termi- 

 nating dorsally at the acicula, which lie slightly below the dorsal border 

 of the neuropodia. In the middle region the neuropodia (PI. XV, fig. 9) 

 are somewhat longer than in the anterior region, but otherwise similar. 

 The notopodia are low, flattened protuberances pushed out anterior 

 to the seta tuft into a pointed, conical acicular process. In the 

 posterior region the parapodia are neuropodial only and are gradually 



