1910.] NATURAL SCIENCES OF PHILADELPHIA. 347 



between tips of parapodia 3 mm. and between tips of setae 4.8 mm. 

 Number of segments 39. 



Prostomium (PI. XXIX, fig. 18) small, depressed, the frontal slope 

 slight and nearly plain, divided for nearly the entire lengtli by a median 

 dorsal furrow; width slightly exceeding length, greatest in posterior 

 half, anterior to that contracted and narrowed into cephalic peaks, 

 which are prominent, acute and widely divergent and ^^■ell separated 

 from the median ceratophore; anterior sinus broad and moderately 

 deep (about one-third prostomial length), continued by dorsal furrow 

 nearly to caudal border. Eyes black, conspicuous but not large; 

 the posterior dorsal and touching or nearly touching posterior border 

 of prostomium, their diameter one-eighth or one-ninth of })r<jstomial 

 width; anterior pair on sides of ])rostomium behind middle, little 

 \'isil:)le from above, looking laterad and slightly forward, in type but 

 little larger than posterior eyes but on other specimeus one-foiu'th or 

 more larger in diameter. 



Median ceratophore (Pl. XXIX, fig. 18) arising in frontal sinus, short 

 and stout, its length not exceeding one-third prostomium and width 

 nearly equal, cask-shaped, scarcely reaching beyond peaks. Style 

 rather stout, not more than twice length of prostomium, basal two- 

 thirds subcylindrical with a very slight subtermiiuil enlargement, 

 nearly the distal third coarsely filamentous; sensory cilia numerous, 

 nearly as long as diameter of style, with slightly bulbous tips. Cerato- 

 phores of lateral tentacles short and thick, situated far back so that 

 they are invisible from above, nearly meeting below median tentacle; 

 styles (fig. 18) less than one-half length of median style, suljulate, the 

 base somewhat thickened but the distal half very slender and delicate; 

 sensory cilia scattered, much shorter than on median tentacle. Palps 

 (fig. 18) also arising far back, al^out three to three and one-half times 

 length of prostomium, rather slender, the base less than one-half 

 width of prostomium, gently tapered to near end, then abruj)tly 

 contracted into a short terminal filament, thickly covered with mimite 

 globoid sensory cilia giving to it a l)rownish coloration. l*\u'ial ridge 

 short and narrow. 



Peristomial parapodia (PI. XXI.X, fig. 18) aclurtous, the tentacular 

 cirrophores not Cjuite reaching level of cephalic peaks; styles exactly 

 like that of median tentacle except that they are slightly more slender; 

 the dorsal equal to median tentacle, the ventral slightly shorter but 

 with the filament relatively longer. Mouth with the usual full, 

 pouting lips. 



Body rather deep, the segments well differentiated and of renuu-k- 



