. Bulletin of the Natural History Museum Zoology. D. Fig. 33. Nuculana acuta. Internal morphology, a. anterior, b, left lateral & c, posterior views of a dissected stomach and combined style sac; d, ventral view of siphonal region. See abbreviations to text-figures on p. 102. Scales = 1mm. broad, elongate, outlined with faint ridge, escutcheon broad, out- lined by rostral ridge; umbos small, inwardly directed, anterior to mid-line; antero-dorsal margin broadly concave, anterior, antero- ventral, ventral and postero-ventral margins form smooth curve, postero-dorsal margin raised, distally s
. Bulletin of the Natural History Museum Zoology. D. Fig. 33. Nuculana acuta. Internal morphology, a. anterior, b, left lateral & c, posterior views of a dissected stomach and combined style sac; d, ventral view of siphonal region. See abbreviations to text-figures on p. 102. Scales = 1mm. broad, elongate, outlined with faint ridge, escutcheon broad, out- lined by rostral ridge; umbos small, inwardly directed, anterior to mid-line; antero-dorsal margin broadly concave, anterior, antero- ventral, ventral and postero-ventral margins form smooth curve, postero-dorsal margin raised, distally straight, proximally - poste- rior to hinge plate - slightly concave, may be slightly upturned in larger specimens; hinge plate elongate, relatively broad, hinge teeth chevron-shaped, up to 18 teeth in each series depending on size of specimen; ligament small, amphidetic, internal pear-shaped in sag- ittal section, extends slightly ventral to hinge plate. The maximum length of the present specimens is Internal morphology (Figs 32, 33) The siphonal embayment is deep, with an elongate tentacle attached to the inner right or left side. The siphons are elongate, combined and except anteriorly, the ventral margins are fused. In the con- tracted state the line of fusion is marked by deep ventral furrow. The anterior sense organ is far anterior, situated at the point where the radial ridge meets with the shell margin. Between the feeding (ventral to the siphonal embayment) and the pedal gape, the inner folds of the ventral margin are applied to each other. In this section of mantle margin approximately 30 small sensory papillae are attached to each middle sensory fold in a specimen total length. The adductor muscles are small the anterior unusually so. The anterior adductor is circular in cross-section and the posterior elongate-oval. The foot is moderately large, elongate, the sole with papillate margins. The heel is not marked but there is a a large 'byssal' gland presen
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Keywords: ., bhlconsortium, bookc, bookcentury1900, bookcollectionbiodiversity
