36 PROCEEDINGS OF THE NATIONAL MUSEUM VOL. 125 
We include here a study of Moore’s original material made when 
describing Chaetozone berkeleyorum. In the holotype of C. gracilis 
(USNM 17398) neuropodial hooks start at about the thirtieth setiger. 
They are smooth and have rounded tips (fig. 72; also checked near 
the fiftieth setiger). The acicular spines are fairly inconspicuously 
arranged and do not encircle the posterior part of the body. The 
accompanying capillary setae (fig. 7g), which are quite similar to 
those in the notopodia, seem to be serrated, but this is irregular 
and might rather be a sign of decay of the setae. The oval eggs are 
up to 120u by 95u. 
Moore’s description fits the holotype only. The cotype (Acad. 
Nat. Sci., Philadelphia, no. 3097) had been dried up at some time 
but is clearly another species. Notopodial capillary setae, slightly 
longer than the body is wide, occur throughout the body. There are 
only capillary setae on the twenty-eighth to thirtieth setigers. The 
neuropodia of posterior setigers (past the hundredth) have only broad 
capillary setae with serration of the edges well visible under 400, 
which are similar to those of Tharyx secundus, new species (p. 37). 
All setae are hyaline. The cotype thus seems to be a Tharyz species. 
Dr. O. Hartman (in litt.) suggested already that the holotype and 
the cotype of Moore’s material may be different forms. 
Neither species is identical with Chaetozone gracilis of Hartman 
(1961). This form is characterized by serrated neuropodial spines 
and is a species to be named. 
Chaetozone setosa Malmgren 
In our material, neuropodial spines occur from the forty-fifth to 
sixty-fifth setigers onward, and even from about the thirty-fifth to 
fortieth in specimens under 1 cm length, whereas Hartman (1961) 
reported for California animals a beginning at the seventy-ninth to 
nintieth setigers. The spines are faintly winged, similar to those of 
C. acuta described above although they are more pointed than in the 
latter species. 
The species occurs at all stations, but, regardless of the sediment 
composition, the intestine is filled with masses of fine detritus, among 
which are some sand grains or diatom frustules that do not surpass 
0.05-0.06 mm in diameter. The species is thus a selective deposit 
feeder, at least in coarse sediment. 
Chaetozone spinosa Moore 
Chaetozone spinosa.—Imajima and Hartman, 1964, p. 297. 
There is one anterior fragment with 36 setigers, which is about 4 
mm long. The first 12 setigers are crowded; the body attains its great- 
