36 
first 18 segments and diminish in size and full¬ 
ness thereafter. Neuropodia are larger and fuller 
than notopodia throughout. In anterior seg¬ 
ments both branches of parapodia are provided 
with only tapering, pointed setae, those in neu¬ 
ropodia thicker and shorter (Fig. 9 b). In the 
postbranchial region, notopodia come to be very 
inconspicuous and are provided with only a 
few slender setae, but their postsetal lobes con¬ 
tinue long and slender (Fig. 9 c). In post- 
branchial neuropodia, setae consist of two kinds 
arranged in a single transverse series; they in¬ 
clude a few long, slender setae, longest superi¬ 
orly, which alternate with thicker, shorter, 
acicular setae with a distal arista (Fig. 9 d). 
The posterior end is unknown. 
A. heteroseta is characterized in having a 
simple prostomial lobe in which the median 
antenna is short; branchiae are present from the 
fourth to thirty-fourth segments and number 
30 pairs; anterior branchial segments have an 
auricular postsetal, notopodial lobe; posterior 
neuropodia are provided with two kinds of setae 
including long, slender, and shorter, acicular 
ones with an arista. The specific name refers to 
the last named character. 
Holotype in the U. S. National Museum. 
Type locality. Lazy Bay, Alaska. 
Distribution. Southern Alaska. 
Family SPIONIDAE 
Genus Laonice Malmgren 
Laonice cirrata (Sars) 
Nerine cirrata Sms, 1851: 207. 
Laonice cirrata Fauvel, 1927: 38, fig. 12; Berke¬ 
ley, 1936: 474; Berkeley, 1942: 196. 
Collection. Station 139-40 (1). 
This species has been recorded from areas in 
the northern Pacific. The present locality is off 
Hallo Bay, in 28 to 40 fm. 
PACIFIC SCIENCE, Vol. II, January, 1948 
Genus Spio Fabricius 
Spio filicornis (Muller) 
Nereis filicornis Muller, 1776: 218. 
Spio minus Chamberlin, 1920: 16B, pi. 3, fig. 
1-4; Hartman, 1938^: 13. 
Spio filicornis Fauvel, 1927: 43-44, fig. 15. 
Spio filicornis pacifica Berkeley, 1936: 475- 
476. 
Collection. Lazy Bay (3 anterior ends). 
No color remains. The prostomium is an¬ 
teriorly truncate, with rounded margins and not 
narrowed forward. Hooded crotchets are first 
present from the seventeenth setigerous seg¬ 
ment. The variety pacifica Berkeley (1936: 
475) appears to be the same, since it is said to 
differ in color only. 
This species was first described from Green¬ 
land but has been reported from many geo¬ 
graphic regions. The present lot is from 
southwestern Alaska, intertidal. 
Genus Prionospio Malmgren 
Prionospio malmgreni Claparede 
Prionospio malmgreni Claparede, 1879: 73-76 
pi. 22, fig. 3; Fauvel, 1927: 61-62, fig. 21; 
Berkeley, 1921a\ 414. 
Collection. Station 72-40 (1). 
The posterior eyes are large, not small; in 
other respects this individual agrees with the 
descriptions. 
This species has been reported from British 
Columbia (Berkeley, 1921 a)\ the present col¬ 
lection is from Cold Bay, in 15 to 50 fm. 
Genus Polydora Bose 
Polydora giardi Mesnil 
Polydora giardi Mesnil, 1896: 195, pi. 13, fig. 
1-12; Fauvel, 1927: 50-51, fig. 17; Hartman, 
1941: 309, pi. 48, fig. 3; Rioja, 1941: 727. 
Collections. Stations 20-40 to 22-40 (4+) 
26-40 (many, in shell fragments); 61-40 
(many, in shell fragments); L 18-41 (1). 
