298
MARINE MOLLUSCS AS HOSTS FOR SYMBIOSES
0.67 min x 0.15 mm ; basal and distal segments of maxilliped subequal
in length with terminal claw which is slender and 0.2 mm long, armed
with a small spine on inner side of base ; fifth leg reaching to posterior
end of genital segment, with one seta and two spines a t tip, and one
subterminal spine on outer margin.
FIGS. 194-197. Clausidiid copepods from Japan. (194) Adult female Panaietis haliotis,
dorsal view; (195) adult male P. haliotis, dorsal view (redrawn after Yamaguti,
1936): (196) adult female Philoconcha amygdalae, dorsal view; (197) adult male P .
amygdalae, dorsal view (redrawn after Yamaguti, 1936).
5 . Philoconcha amygdalae Yamaguti, 1936. (Figs. 196 and 197)
(Order Cyclopoida ; family Clauuidiidae)
Philoconcha amygdalae, the genotype, was described by Yamaguti
(1936) based on two mature males, one gravid female, and some immature specimens found in Tapes semidecussata from Tiba Prefecture,
Japan. Their exact location within the pelecypod was not reported.
Description. Adult female (Fig. 196) up to 6.6 mm long, with greenish digestive tract ; head approximately triangular, with strongly
convex sides, sharply demarcated from first thoracic segment in
immature specimens but more or less fused in adults and measuring
1.2 mm wide a t its somewhat prominent posterolateral corners ;
frontal margin prominent, with rostrum projecting ventrad between