362 PROCEEDINGS OF THE ACxVDEMY OF [April, 



fine o-ray sand; 4,463, Monterey Bay, off Point Pinos Light, 48-111 

 fathoms, rocky; 4,532, same, 30 fathoms, gray sand and rocks. 

 Nemidia microlepida sp. nov. Pi. XXX. figs. 42-44; PI. XXXI, figs. 45, 46. 



The single specimen known fortunately retains the full number 

 of segments and is a long, slender, depressed worm of very even width. 

 Numljer of segments 85; length 58 mm.; width at X, body only 2.5 

 mm., spread of parapodia 7.2 mm. ; at L, body 2 mm., spread of para- 

 podia 6.8 mm. ; greatest depth about 2 mm. 



Prostomium (Pi. XXX, fig. 42) small, slightly wider than long, 

 greatest width a little behind the middle where the sides project 

 prominently; anterior to this point the sides are straight and con- 

 verge strongly to the minute peaks which lie very close to but free 

 from the median ceratophore; anterior fissure rather deep but com- 

 pletely filled by the median ceratophore which is soldered to the 

 prostomial lobes, not more than its distal third being free. Eyes 

 wanting. Median tentacle stout and swollen in the middle, coni- 

 pletel}' filling cephalic sinus and coalesced with the prostomium, on 

 the dorsum of which it rises as a ridge, the distal third free. Style 

 short, about one and one-third times length of prostomium, rather 

 slender, the distal one-third tapering to a short filament. Lateral 

 tentacles (fig. 42) arising from short, thick ceratophores which are 

 united in the median line below the median ceratophore, at the sides 

 of which they are largely exposed; styles short, rather stout and 

 subulate, tapering to very short terminal filaments, their length one- 

 half or less of median style. Palps (fig. 42) imperfect from sloughing 

 of their ends, rather siiort, little exceeding t^\ice head, thick, little 

 tapered till near end, terete and perfectly smooth, without sensory 

 cilia. 



Peristomial parapodia (PI. XXX, fig. 42) short and thick, diverging 

 above base of palps, supported by a single stout acicidum, the tip of 

 which appears in a dorso-median position; apparently achatous; 

 cirrophores united nearly to their ends; styles like median tentacle 

 and the dorsal of equal length, the ventral slightly shorter, both rather 

 stout, tapered to a short terminal filament and lacking sensory cilia. 



Body narrow, at widest part only one-third of width between ends 

 of parapodia and posteriorly, where the parapodia are longer, much 

 less than that; tapering very gently and regularly caudad. Seg- 

 ments well defined, each bearing on the doreum two prominent, 

 blunt, median papilla? in tandem, all together forming a series which 

 becomes higher and more crowded posteriorly, finally constituting 

 an almost continuous serrated crest. On the ventral side the usual 



