Dasianglan, Taipei County, 2 Aug 2007: 29 specimens (BD 6.90-13.24 mm) (CEL- BB-123).—Badouzih, Keelung City, 30 Jul 2008: 4 specimens (BD 9.26-10.70 mm) (CEL-BB-124).
Shell with 6 plates, base calcareous, shell grey or light-brown parietes, on which black spots may be seen in some individuals; orifice rhomboidal. Scutum and tergum strongly articulated forming a sinuous line; scutum elongated and triangular, tergal margin strongly articulated; tergum narrow, basi scutal angle almost 90°. Mandible with 3 large teeth, inferior angle excluded; pectinated lower angle with 48 small teeth; labrum with a row of 10-12 large teeth on concave edge, covered with smooth setae; mandibulatory palps and maxillules with long, smooth setae. Anterior and posterior rami of cirrus I short, with 4 segments on posterior and 6 segments on anterior ramus, dorsal surface of anterior and posterior rami with conical spines, ventral sides of anterior and posterior rami of cirrus I with serrulate setae; cirrus II with multicuspidate setae; cirri III-VI similar; dorsal side of cirrus III with short, smooth, open-ended setae; ventral side of cirrus with both long and short smooth setae.
Coloration.—Shell grey or light-brown parietes, black spots may be seen in some individuals.
BD to 15 mm.
Japan (including Okinawa), Taiwan.
On high shores of exposed rocky shores.