Fossils from the Upper Musashino of Kazusa and Shimosa. X35 



a lialf the height. But in the fossil specimens the length is gene- 

 rally five times the height or even a little greater. The upper 

 margin (hinge-margin) is often somewhat concave, though it is 

 usually straight. 



The fossil specimens are generally somewhat smaller than 

 the living, the largest measuring 80 millim. in length and 15 

 millim. in height. 



Fossil occurrence. — Otake (very frequent), Shisui (do), Kame- 

 nari, Tega, Shito, (very frequent). Oji, Tahata and Shinagawa in 

 ]\[usashi. 



Living. — Northern Japan. ''" 



Genus SltlQUA, Müblfeld. 



•^07. Siliqua ptUehella, (Duiiker). 



PL IX. Fig- 7. 



Siliqua pidcheUa. Pilsbry, Catalogue, p. 12 1 . 



Anlus inilchellus. Danker, Zeitschrift für Malakol., 1852, p. 58. Nov. Conch., pt. II, 

 p. 20, pi. YI, tigs. 4, 5. Ind. Moll., p. 174. Lischke, Jap. Meeresconch., II, p. 

 124. 

 MacJuem pitlchella. Clessin, Mart. ii. Chem Syst. Couch. Cab., vol. XI, pt. 3, Solenacea, 

 p. 65. pi. XX, fig. 6. 

 The shell is thin, fragile, transversely much elongated, 

 suhelliptical, very inequilateral, smooth (in fresh state with fine 

 radiating lines except on the posterior surface), with a strong inner 

 ril) which runs from the beak to the ventral margin. 



Most of the specimens have the length a little greater than 

 three times the height, but there is one from Tega which is shorter, 

 the length being not quite three times the height. It is probably 

 due to variation. 



Fossil occurrence. — Otake (pretty frequent), Tega. 

 Living. — Central and Western Japan. 



• Pilsbry mentions Akashi as one of tlie habitats of A. fertfsgn.sffrîiii (Catalogue, p. 190) 

 on the authority or Stearns. But it is evidently a mistake for Akke^hi (Northern Japan). 



