Jumars, P.A. - University of Maine

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P. A . JUMARS
E
F
Figure 12 . Ophryotrocha hadalis sp . nov : A, parapodium 10 ; B, anterior in dorsal view, left palp
and antenna missing ; C, simple seta of parapodium 10 ; D, compound seta of parapodium 10 ;
E, compound seta of parapodium 20 ; F, entire maxillae in dorsal view with denticle rows spread
apart ; G, mandibles in dorsal view . A-E are from the holotype ; F and G are from the paratypes .
present on the prostomium (Fig . 12B) below the level of the antennae . The
palps are inserted laterally just anterior to the first peristomial ring . Eyes are
absent . Parapodia (Fig . 12A) lack dorsal cirri ; ventral cirri are short and digitate
from the first parapodium . Setae become progressively thinner, longer, and
smoother in proceeding from anterior to posterior setigers . Capillaries are
always present dorsally on the neuropodium . Those in the anterior few setigers
are denticulate as are the distal ends of the shafts of the compound falcigers
(Fig . 12C,D) . The decrease in thickness of more posterior setae is associated
with the loss of all denticulation and a gradual change from short-appendaged
falcigers to long-appendaged spinigers (Fig . 12E) . The pygidium is unknown .
Carriers and basal plates all appear fused (Fig . 12F) . In each of the two
denticle series, four denticles are plate like and two are falcate . The former
clearly belong to the inferior row and the latter clearly belong to the superior
row . One additional denticle in each series appears to be the result of fusion of