13'2 ^^^- l.-M. Yokoyama: 



SOO. JPeefeit iiifuseosfafus, Yokoyaina. 

 Fecten inliisctMcitus. Yokoyaiua, Foss. Miura Peniu., p. 15G, pi. XIII, figs. 9, 10. 



Tiiis small shell already described from the Lower Musashino 

 has the outer sm*face concentrically striated, while within tliere are 

 coarse distant radiating riblets near the margin. 



Fossil occurrence. — Sliito (not rare). Lower j\[usashino of 

 Miyata and Koshiba. 



SOI. Pee fen fohijoensis, Tokunaga. 



Fecteti tnkifoemis. Tokunaga, Foss. Env. Tokyo, p. G8, pi. V, figs. 1-10. Yokoyaina, 



Foss. Miura Penin., p. 158, pi. XIV, figs. 7, 8. 

 Pecten jylic'ä.. Brauns, Geol. Env. Tokio, p. 48, (non Linné). 



Tliei-e are many large specimens, the largest being more than 

 160 millim. liigh. 



Fossil occurrence. — (Hake, Shito (veiy frequent). Oji 

 (frequent) and Shinagawa. Lower Musashino of ^Mij^ata, 

 Yokosuka and Naganuma, 



S02. JPecfen fisttofi, Beriiardi. 



PI. XV. Fji-'s. 1, 2. 



Pevten tissoti. Pilsbry, Cat., p. 144. Bernardi in Jour. d. Conch., VII, 1859, p. 91, 

 pi. I, fig. 2. Kobelt in Syst. Concb. Cab., VII, part 2, Spontlylns and Pecten, p. 

 143, pi. XL, fig. 5. 



A small neat Pecten circular in form and tolerably svvullen, 

 with the anterior ear larger than the posterior. About twenty 

 radiating ribs accompanied by a smaller one on both sides 

 ornament the surface. Crossing these ribs, there are fine 

 concentric lamellae which are most distinct in interspaces where 

 there are one or two radiating striae. Inner margin crenate. 



Only three valves of wliicli two are right. The larger of the 

 right valves measures 1().<S millim. in height, 16 millim. in breadth 

 and 0.2 millim. in depth. 



Fossil occurrence. — Shito. 



Living. — Japan (according to Lunker). 



