NO. 3667 POLYCHAETES—BANSE AND HOBSON 29 
(fig. 6e) begin on the sixteenth to seventeenth setiger in young and 
mature specimens. There are fewer than 10 hooks per parapodium. 
Two ventral stout bristles start from the thirty-second or thirty-third 
setigers. Notopodial hooks are absent. There are four anal cirri (fig. 
6f), round in cross-section and about 0.4 mm long. 
Two large brown pigment spots occur on the prostomium behind 
its anterior constriction; sometimes similar pigmentation is present 
also on the anterior end of the lateral wings of the prostomium. There 
is some irregular pigment pattern dorsally behind the prostomium, 
and a thick band of pigment is found laterally on the peristomium. 
In the first 8 to 10 setigers, some brown pigment occurs in the inter- 
segmental borders between the neuropodia and ventrally on both 
sides of the midline, separated by the pigment-free midline. 
Polygonal eggs of about 250u diameter are observed in one specimen 
(February). The animals construct a transparent fragile mucus tube. 
The name refers to the presetal notopodial cirrus. 
Diaenosis.—A Paraspio species with an anteriorly rounded 
prostomium. Notosetae and a small gill on the first setiger. Dorsal 
presetal cirri in the anterior region of the body. Tridentate neuro- 
podial hooks from setiger 16 or 17, ventral neuropodial acicular 
setae from setiger 32 or 33. Four elongated anal cirri. 
DiFrFERENTIAL DIAGNOSIS.—The new species may be distinguished 
from the members of the genus listed by Hartman (1959, 1965b; 
including Microspio) as follows: P. africana (Rullier), P. armata 
(Thulin), P. minuta Hartmann-Schréder, P. kussakini (Chlebovich), 
P. theeli (Séderstrém), and P. wireni (Augener) do not have tri- 
dentate hooks. Among the Paraspio species with tridentate hooks, 
P. mecznikourana (Claparéde) and P. rolasiana (Augener) lack 
setae in the first notopodium (as does P. minuta); P. arctica (Séder- 
stroém) has a pointed prostomium (as does P. theeli). The presetal 
dorsal cirrus has been reported only for P. africana and P. atlantica 
(Langerhans); the latter species has been separated from P. arctica 
by Hannerz (1956). Paraspio africana has unidentate hooks and 
peculiar liimbate notosetae; P. atlantica has a rather pointed pros- 
tomium, and its tridentate hooks start on the ninth segment. 
Prionospio pinnata Ehlers 
In our material, the third pair of gills is always only half as long as 
the first two pairs. There is no appendix on the third pair of gills as 
reported by Caullery (1915) for Malayan material. 
Ehlers (1901) has implied that the species is a selective deposit 
feeder. Specimens from station 3 (mean grain size diameter 0.126 mm) 
have numerous sand grains not exceeding 0.07 mm imbedded in fine 
detrital material, which confirms Ehlers’ observation. 
