﻿ANODONTA 409 



are sometimes slightly corrugated ; dorsal wing only moder- 

 ately developed, sometimes angled behind, occasionally round- 

 ed ; posterior slope generally slightly truncated ; posterior ridge 

 low, often double and ending in a feeble biangulation behind ; 

 epidermis generally brown, occasionally feebly rayed ; nacre 

 white, bluish-white, or purplish. 



Length no, height 70, diam. 45 mm. 



Japan. 

 Anodonta laiita von Martens. S. B. Nat. Fr., 1877, p. 117: 



Abh. Senck. Nat. Ges.. X. 1877, p. 152, fig. i. — Kobelt, Abb. 



Senck. Nat. Ges., XI, 1870. p. 434, pi. xxi, fig. i. — Simpson,, 



Syn.. 1900, p. 639. 

 Anodonta ivoodiana Kor.Ei,T, Abh. Senck. Nat. Ges.. XI, 1879, 



p. 433, pi. XX, fig. T. 



A very variable form distinguished typically by its rather 

 regular, elliptical outline and by its dark, generally rayless. 

 epidermis. The surface has more or less of irregular concen- 

 tric sculpture. It approaches very close to A. calipygos and 

 there are specimens that I can scarcely refer to either species. 

 It is generally less inflated and has lower beaks than that spe- 

 cies. Kobelt figured and described a form in the Fauna Ja- 

 ponica Extramarina. which he referred to the Anodonta wood- 

 iana of Lea. It certainly is not that species, which is much 

 produced at the posterior base and sharp behind. I believe it 

 to be a form of A. lauta with compressed beaks. 



Var. rostrata Kobelt. 



More pointed behind, with a stronger, more acutely angled 

 post-dorsal wing, and fuller at the posterior base than the type. 

 Anodonta lauta var. rostrata Kor.Ei.T. Abh. Senck. Nat. Ges., 



XL T879. p. 435. pi. xxiT, fig. I. 



\'ar. tnmens (Haas). 



"A highly inflated form of A. lautiis Marts., characterized 

 by the strong ridges of the beak-sculpture, which, on the upper 

 part of the disk, become very high and nearly terraced-shaped. 



