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PACIFIC SCIENCE, Vol. XVIII, April 1964 
TABLE 3 
Characteristics of Polydorids 
MODIFIED 5TH SEGMENT 
HOODED HOOKS 
Degree of 
Setal 
GENUS 
BRANCHIAE 
Begin 
Shape 
Modification 
Arrangement 
Polydora 
post. 5 th — absent 5 th 
7 
bifid 
great 
not U-shaped 
Boccardia 
ant. 5 th — absent 5th 
7 
bifid 
great 
not U-shaped 
Pseudopolydora 
post. 5 th — absent 5th 
8 
bifid 
less 
are U-shaped 
Tripolydora 
ant. 5th — present 5th 
9 
trifid 
slightly 
not U-shaped 
chaetous annelids of the world (Part II), employs 
separate genera for Poly dor a, Boccardia, and 
Pseudopolydora. The latter, from Czerniavsky in 
1881, is given priority over Carazzia of Mesnil 
in 1896. 
In this paper the arrangement follows that 
of Hartman. The author is of the opinion that 
the tendency to accept Boccardia as a separate 
genus on the basis of branchial arrangement and 
to retain Pseudopolydora [—Carazzia'] as a 
subgenus is not supportable, for the latter have 
a specialized 5 th segment less modified than 
that in members of the other two groups; and, 
quite significantly, the hooded hooks begin not 
on Segment 7 but on Segment 8. If the separa- 
tion of one genus is accepted, then both should 
be accepted. Thus, it would seem that, according 
to an individual’s taxonomic approach, there 
should be three separate genera or one genus 
with three subgenera. 
The appearance in these collections of mem- 
bers of a new but closely related genus has not 
helped to clarify the relationships between the 
respective genera, as Table 3 illustrates. 
Polydora and Boccardia are similar in general 
appearance and in extreme modification of the 
5th segment; however, they vary in branchial 
arrangement. Pseudopolydora and Tripolydora 
are similar in general appearance and modifica- 
tion of the fifth, but vary in general branchial 
arrangement, setal arrangement in the fifth seg- 
ment, and segmental appearance of hooded 
hooks. Both Boccardia and Tripolydora have 
branchiae anterior to the 5th, but vary in hooded 
hooks ( segmental appearance and shape ) ; and 
the latter is the only genus whose members have 
branchiae on the 5 th segment. 
With the acceptance of these four genera (or 
subgenera) the position of two other species 
becomes problematical. 
In Polydora commensalis Andrews (1891) 
the hooded hooks do not appear until Segments 
12-14. This form was placed in Polydora be- 
cause the branchiae begin posterior to the modi- 
fied fifth; however, they begin on Segment 6 
and in most fully described members of this 
genus the branchiae are first present on Segment 
7. Polydora commensalis has a highly modified 
anterior end, an unusual pygidium, and may be 
sexually dimorphic. The hooded hooks of Poly- 
dora citrona Hartman (1941) begin on Segment 
10 and its prostomium and pygidium are un- 
usual. If one separates the genera (or subgenera) 
of Polydora and Pseudopolydora on the basis of 
appearance of hooded hooks on Segments 7 and 
8 respectively, the taxonomic position of P. 
commensalis and P. citrona must be re-examined. 
REFERENCES 
Andrews, E. A. 1891. Report upon the Anne- 
lida Polychaeta of Beaufort, North Carolina. 
Proc. U. S. Nat. Mus. 14:277-302. 
Berkeley, E. 1927. Polychaetous annelids from 
the Nanaimo District, 3. Leodicidae to Spi- 
onidae. Contr. Canad. Biol. Ottawa, n.s. 3: 
405-422. 
and C. Berkeley. 1952. Annelida; 
Polychaeta Sedentaria. Can. Pac. Fauna 9b: 
(2) : 1-139. 
Bose, L. A. 1802. Histoire Naturelle Des Vers, 
Contenant Leur Description Et Leurs Moeurs; 
Avec Figures Dessinees D’Apres Nature. 1: 
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