NO. 3 HARTMAN: SUBMARINE CANYONS 51 



Chaetozone armata, new species 



San Pedro sea valley, dredged' in 180-430 m (1, HOLOTYPE), 

 522m (1). 



This is a small, linear form; it measures 13.5 mm long for 72 

 segments (a posterior end is missing). It is widest in the anterior 

 fourth of the body where it is about 0.68 mm across, and 0.48 mm 

 wide in the postmedian region. The anterior region (Fig. 3a) is de- 

 pressed cylindrical in cross section and its setal fascicles are directed 

 laterally. In posterior segments the body appears moniliform because 

 it is slenderer and the individual segments are proportionately longer; 

 in cross section (Fig. 3b) the segments are subquadrate because 

 the acicular spinelike setae are directed outward from the ectal margins. 



The prostomium is long, triangular, about 3 times as long as 

 wide. A pair of small black eyespots, one on either side of the raised 

 median prostomial ridge but not visible in dorsal view ; they are em- 

 bedded and located near the posterior end of the lobe. The paired 

 palpi for which the bases can be distinguished are inserted dorsally 

 on a short segment in front of the first setigerous one. 



Setal fascicles are first present behind the palpal ring. The first 

 16 segments have only slender, distally pointed setae that number six 

 or more in a fascicle. Thicker, shorter yellow acicular setae are first 

 present in segment 17, together with slender pointed setae, and within 

 a few segments the pointed setae are almost completely replaced by 

 single acicular spines. An occasional long, slender seta is present farther 

 back, to segment 25 or to 36, but it is very slender and inconspicuous. 



The posterior, moniliform segments are armed with single, curved 

 spines in notopodia and neuropodia; they project obliquely upward 

 and downward (Fig. 3b) from the setal fascicle. Seen individually 

 (Fig. 3c) they have an entire tip and a slight shoulder in the embedded 

 part. 



Chaetozone armata may be distinguished from other species of the 

 genus (Hartman, 1961, p. 104) by having moniliform posterior seg- 

 ments, and parapodia provided with single, acicular, distally curved 

 spines in which the free end is curved. The type specimen originates 

 in San Pedro sea valley (Velero IV Sta. 7175-60) in depths below 

 180 meters. 



Chaetozone spp. 



Monterey en, in 260 m ( 1 ) . 



Redondo en, axis, in 344 m (2 jv) . 



Newport en, in 16 m (12 small), 642 m (1 fragment). 



Coronado en, in 1265 m ( 1 ) . 



