Altiverruca navicula (Hoek, 1913)

Figures 2 E, 21, 22

Verruca navicula Hoek, 1913: 134, figs 4–6. — Nilsson-Cantell, 1927: 778, figs a–f. Altiverruca navicula . — Buckeridge, 1994: 100, fig. 5.

Material examined. NMNS 005087-00077, 1 specimen, Stn. CP285 (24º16.09’N, 122º11.52’E, 16 Jun. 2005, depth 2268–2426 m), BD 11.37 mm.

Diagnosis. Rostral and carinal apices marginal; myophore absent from fixed scutum; operculum nearly vertical to base; movable scutum and movable tergum interlocking with 4 ribs, caudal appendages long.

Description. Shell white, rostral and carinal apices marginal, carina and rostrum interlocking in a single rib; movable tergum quadrangular, scutal margin with 5 ribs, apex curved; movable scutum triangular, tergal margin with 4 ribs, apex curved (Fig. 2 E). Maxilla bilobed, with dense setae, sparse setae along superior margin (Fig. 21 A); maxillule with strong, wide notch on cutting edge, 2 large cuspidate setae above notch, dense setae in notch, 7 setae below notch (Fig. 21 B); mandible with 3 teeth (Fig. 21 C), lower margin long, with> 8 small, cuspidate setae, inferior angle pectinate, with cuspidate setae at angle (Fig. 21 E); mandibular palp elongated, dense setae along superior margin (Fig. 21 D); labrum slightly concave, fine, bi-dentate to quadridentate teeth on cutting margin (Fig. 21 H). Cirrus I with rami unequal, outer ramus elongated, 27- segmented, inner ramus shorter, 15-segmented (Fig. 22 A); cirrus II with rami unequal, outer ramus 27- segmented, inner ramus 11-segmented (Fig. 22 B); cirrus III with outer ramus 30-segmented, inner ramus 27- segmented (Fig. 22 C); cirrus VI with outer ramus 36-segmented, inner ramus 37-segmented (Fig. 22 D); caudal appendage long, 34-segmented (Fig. 22 D).

Distribution. Pacific Ocean

Remarks. This is a new record for Taiwanese waters.