1917] Essenberg: Some Species of Aphroditidae 405 



deep furrows on eaeh side and extends to tlie third segment. The 

 dorsum is covered with a thick, felty layer; beneath this are fifteen 

 pairs of tough, widely overlapping elytra (pi. 31, fig. 10) covering 

 the entire dorsum. They are arranged in the usual order character- 

 istic of the genus and are partly covered with brown pigment. The 

 fimbriated organs (pi. 31, fig. 12) are hatchet-shaped, consisting of 

 three or more lobes, each lobe having two or three short projections. 



The ventral and dorsal surfaces are studded with papillae. The 

 latter are simple, without the caps (pi. 31, figs. 13, 14). The para- 

 podia are biramous (pi. 31, fig. 11). The notopodium is a mere pro- 

 tuberance. The neuropodium is very long and slender. The neuro- 

 setae, which are arranged in the usual three series, are very dark 

 brown, almost black, and are very long. The dorsal row consists 

 of two stout setae, the ends of which are tapered, slightly curved, 

 and pillose (pi. 31, figs. 2, 2'). The median row has four setae, equal 

 in structure to the former, but smaller in diameter (pi. 31, fig. 4). 

 The six setae from the ventral series are lighter brown in color, 

 .smaller in diameter, with a subterminal enlargement ending in an 

 attenuated, curved, and richly pillose extremity (pi. 31, fig. 3). The 

 neurosetae of the second parapodium are specially modified with long, 

 dentate projections (pi. 31, fig. 6). The caudal neurosetae are long, 

 ending bluntly, with the distal jiortion covered with conspicuous pro- 

 tuberances (pi. 31, figs. 5, 5', 5"). The notosetae are in two rows, 

 the lateral ones forming a fan-like ai'rangement pointing dorsally. 

 The dorsalmost are very long, with colorless, slightly hooked tips (pi. 

 31, fig. 9), meeting in the dorsum or overlapping. The notosetae are 

 covered with asperities, which are visible only under higher magnifica- 

 tion (pi. 31, fig. 7). Some of the dorsal setae near the posterior 

 extremity end more bluntly and are surrounded by a gelatinous 

 envelope (pi. 31, fig. 8). 



The lateral fibers are short, coarse, and colorless. They are sparse 

 and do not conceal the neuropodia. The long fibers form a heavy, 

 felt layer over the dorsum. 



The neurocirrus arises from the parapodium at a point about 

 two-thirds of its length from the body; it is only about one-fourth 

 of the length of the notocirrus (pi. 31, fig. 11). 



Occurrence. — The two specimens, type and cotype, were found 

 at Station 1124 at 32° SSfl N, 117° 18:5 W, off La Jolla, California, 

 at a depth of 292 metres, on green mud bottom, June 25, 1906. 



