404 PROCEEDINGS OF THE ACADEMY OF [June, 



tically the normal length. The form is slender and tapers ver}^ 

 sUghtly to the caudal end. The total length is 24 mm., the maxi- 

 mum width of the body 2 mm., and between the tips of the parapodia 

 4.5 mm. 



Prostomium about as broad (across the ocular lobes) as long, marked 

 for its entire length by a median dorsal groove wliich widens anteriorly 

 to a broad and deep cleft separating the rounded frontal lobes or peaks ; 

 the narrowest part of the prostomium is at the posterior border, ante- 

 rior to which the lateral borders diverge, then swell out abruptly at 

 about the middle as prominent rounded lobes which bear the anterior 

 pair of eyes. Ceratophores of tentacles nearly spherical, possibly the 

 result of contraction ; the median crowded between the cephahc peaks 

 into the frontal cleft; the lateral partly beneath the median and well 

 below the peaks ; style of median antenna lost ; the lateral very short 

 and thick, scarcely longer than its ceratophore, and its diameter equal 

 to ^ its length, ovate pyriform and little pointed. Palpi slender, 

 tapered regularly to tip, about 2| times length of prostomium. Eyes 

 2 pairs, both very large, especially the anterior, but hghtly pigmented, 

 the anterior pair situated on the ocular lobes, the posterior shghtly 

 caudad and mesiad, and nearly or actually in contact mth the anterior. 



Tentacular cirri, or at least the ventral, which alone remain, about 

 ^ as long as palpi, to which they have a similar form, with the distal 

 half more slender. There are 57 somites in addition to those in regen- 

 eration, and all but the peristomium and pygidium are setigerous. 

 Ventral surface smooth, sole-hke, with rounded margins separated from 

 the bases of the parapodia by a groove on each side. No visible 

 nephridiopores or papillae. Elytrophores prominent, nearly cylindri- 

 cal or shghtly tapering; the median space of the back scarcely exceed- 

 ing in width their diameter. 



Parapodia large and prominent, similar throughout the series, except 

 that the dorso-ventral diameter decreases toward the posterior end. 

 NeuropocUum much larger than notopodium, broad, flat, leaf-hke, its 

 lateral margin broadly rounded, the ventral convex, and dorsal con- 

 cave, so that as a whole it appears to have a slight curvatm-e dorsad; 

 at the end it is split into two vertical plates, both, especially the pos- 

 terior one, being very thin and embracing the bases of the setae between 

 them for a considerable distance. Notopodium a rounded lobe arising 

 from the anterior side of the dorsum of the neuropodium about its 

 middle. Like the el5^rophores, the dorsal cirrophores are remarkably 

 large; although arising much nearer the base of the parapodia they 

 reach as far laterad as, and at the same time much dorsad to, the noto- 



