﻿224 CKISTAKIA 



CUISTAKIA I'l.lCATA ( Lcacll ) . 



Shell very larije, somewhat rhomhcMil. thin or suhsohd, not 

 inrtated. with low. compressed heaks, whose sculpture consists 

 of a few feeble ridj^es runnins;" nearly parallel with the g"rowth 

 lines and fading' out at the |)osterior ridge ; posterior ridge 

 rather high and rounded in the earlier stages of growth, nearly 

 obsolete below on older shells ; there is a sharply angled, some- 

 times elevated wing in front and a high one with an irregular 

 dorsal border behind ; surface greenish-yellow to pale or brown- 

 ish-olivaceous, faintly rayed in the young shells ; posterior dor- 

 sal plications strong, showing inside and out and extending 

 from the beaks to the hinder end of the laterals ; post-dorsal 

 region obliquely truncate, the outline straight in young shells, 

 incurved in old ones ; posterior end sometimes slightly biangu- 

 late ; escutcheon large ; each valve has a single short lateral ; 

 beak cavities shallow, with a row of scars pointing towards the 

 anterior base; muscle scars shallow, the anterior irregular; 

 nacre dull whitish, often blotched, thicker in front in old shells. 



Length 230, height including wing 176, without wing 142, 

 diam. 60 mm. 



China ; Japan ; Amurland, south probably to Cambodia. 

 Dipsas plicatus Leach, Zool. Miscellany, I, 1815, p. 120, pi. 



1,111.— So WEKBY, Conch. Man., 1839, fig. 142. — Chenu, Bib. 



Conch., 1st sen, III, 1845, p. 15, pi. vi, fig. i.— Heude, 



Conch. Fl'uv. Nank., 1879, pis. xxxiii, xxxiv, 1,1, fig. 94. 

 Mytilus plicatus Solander, in Gray, Ann. of Phil., IX, 1825, 



p. 27. 

 A p pins plicatus GRA^ , in Menke. Syn. Meth. Moll., 1830. p. 



106. 

 Margarita (Dipsas) plicatus Lea. Syn.. 1836, p. 47; 1838, p. 



28. 

 Mari^aron (Dipsas) plicatus Li:a, Syn., 1852. p. 46: 1870, p. 74. 

 Unio plicatus Soweri'.y. Conch. Icon., XVII, 1868, pi. i.iv, fig. 



280. 

 Dipsas plicata Komki.t. Ahh. Senck. Nat. Ges., XT, 1879, p. 



429, pis. xv-xvii, XVIII, fig. I. 



