1910.] NATURAL SCIENCES OF PHILADELPHIA. 351 



margin. Frequently the smooth tips of both notopodial and neuro- 

 podial seta? are even longer than indicated by Johnson's figures. The 

 accessory tooth of the latter is best developed on the dorsal rows and 

 frequently absent on the ventralmost two rows. The palpi are 

 slightly angulated by six raised longitudinal lines bearing cilia. One 

 of the most striking superficial characters of this species is the promi- 

 nence of the notopodial setae. 



Stations 4,420, off San Nicolas Island, 32-33 fathoms, fine gray 

 sand; 4,496, Monterey Bay, off Santa Cruz Light, 10 fathoms, fine 

 gray sand, rocks. 



Harmothoe tenebricosa sp. nov. PI. XXIX, figs. 23-28. 



A rather broad and strongly depressed species with long, laterally 

 directed parapodia. The type, like one of the two largest specimens, 

 has 41 segments, is 35 mm. long and at somite X has a width of body 

 of 4 mm., between tips of parapodia of 9.5 mm. and between tips of 

 setae of 14 mm. 



Prostomium (PI. XXIX, fig. 23) about one-fifth wider than long, 

 strongly arched above, sloping forward from the prominent posterior 

 region; greatest width near posterior end, the sides strongly convex; 

 anterior border depressed in middle, with a wide fissure from which a 

 furrow extends for a short distance caudad; at a distance from the 

 fissure equal to its width the blunt peaks rise rather abruptly and 

 project prominently forward freely above the bases of the palps and 

 lateral tentacles. (One specimen has the peaks retracted and little 

 prominent and another (sta. 4,528) has the prostomium less con- 

 tracted anteriorly and more quadrate in form.) Eyes totally wanting. 

 Frontal ridge and tubercle very conspicuous, mouth trilobate, sur- 

 rounded by very prominent protuberant furrowed lips. 



Ceratophore of median tentacle (fig. 2S) arising from frontal fissure, 

 cvlindroid, short, projecting only a little way beyond the peaks; 

 style less than three times length of prostomium, moderately slender 

 with a faintly indicated subterminal enlargement and a rather long, 

 slender subterminal filament. Ceratophores of lateral tentacles at 

 level of palps and partly covered by median tentacle, reaching nearly 

 to end of median ceratophore; styles scarcely longer than prostomium 

 the basal half or more tapered, the rest filamentous. Sensory papillae 

 absent or nearly so from all cephalic appendages. Palps slender, 

 regularly tapered, from three to five times length of prostomium 

 according to state of contraction or extension in different specimens ; 

 filamentous tip very short, no longitudinal ridges or lines of sensory 

 cilia. 



