354 PROCEEDINGS OF THE ACADEMY OF [April, 



between tips of parapodia about 5 mm., and between tips of seta\ 

 7.2 mm. Number of segments 37. 



Prostomium (PI. XXIX, fig. 29) as wide or slightly wider than long. 

 depressed, frontal slope moderate, divided by a median dorsal furrow 

 for most of length, the halves smoothly rounded; postocular region 

 somewhat contracted but concealed by a membraneous nuchal fold; 

 greatest width slightly anterior to middle and occupied by prominent 

 ocular swellings anterior to which is a rather abrupt constriction 

 sloping immediately into the peaks. Cephalic peaks usually rather 

 large and prominent, with steep medial slopes and blunt apices separated 

 from the median ceratophore by an internal not exceeding three- 

 fifths diameter of median sinus which reaches nearly to the center of 

 the prostomium and is continued into the dorsal furrow. Eyes two 

 pairs, both large and prominent, black; the posterior one-sixth to 

 one-eighth width of prostomium, facing nearly dorsad at posterior 

 lateral angle, separated from concealed caudal border of prostomium 

 by nearly their diameter and from each other by three to five times 

 their diameter ; anterior eyes one-fourth to one-sixth width of prosto- 

 mium, on sides of ocular swellings anterior to middle and seen from 

 above only through the tissues of the head, separated from posterior 

 eyes by one to one and one-quarter times the diameter of the latter. 

 Some specimens have the eyes even larger and they are always con- 

 spicuous although the anterior are little visible from above. 



Median ceratophore (Pi. XXIX, fig. 29) about one-half length of 

 prostomium but deeply inserted into sinus and scarcely reaching 

 beyond peaks; style unknown, missing from all specimens. Cerato- 

 phores of lateral tentacles cylindroid, fully half as long as median 

 ceratophore but owing to position well back on ventral face of pros- 

 tomium they are usually completely concealed in dorsal view by the 

 cephalic peaks; styles nearly three-fourths length of prostomium, 

 subulate, the distal one-third slender; sensory cilia elongated and 

 enlarged. Palps about three to three and one-half times prostomial 

 length, rather stout at base, where their diameter nearly equals one-half 

 width of prostomium, smooth or often annulated. tapered to a short 

 terminal filament and bearing a few lines of very small globoid sensory 

 cilia. Facial ridge moderately prominent, reaching into mouth, 

 which is surrounded by the usual prominent trifid lips. 



Peristomium obsolete above, its rather small parapodia bearing 

 a small tuft of notopodial setse and its cirrophores not quite reaching 

 level of prostomial peaks, largely concealed by notopodial setae of II 

 which spread over them; styles (PI. XXIX, fig. 29) unusually slender. 



