Fossils from the Miura Peninsula and its Immediate North. 167 



216. Area inflata, Eeeve. 

 Pl. XVII. Fig. 9. 



Area inflata. Reeve, Conch. Icon., Area sp. 30, pl. V, fig. 30. Kobelt in Syst. Conch. 

 Cab., vol. VIII, p. 30, pl. 10, figs. 1, 2. Lischke, Jap. Meeresconch., I, p. 146. Brauns, Geol. 

 Env. Tokio p. 44. Tokunaga, Foss. Env. Tokyo, p. 57, pl. Ill, fig. 19. 



Area broughtonii. Schrenck, Moll. Amurl. u. d. Nordjap. Meeres, p. 578, pl. 24, figs. 1—3. 



Area tenuis. Tokunaga, Foss. Env. Tokyo, p. 58, pl. IV, fig. 1. 



A large specimen, 110 millim. long, 85 millim. high and 77 

 millim. thick, with forty-two ribs and a moderate-sized area. 

 According to Yamakawa (Jour. Geol. Soc. Tokyo, vol. XVIII, 

 no. 209, Scapharca) this species is distinguished from Area satowi 

 Dunker (Index Moll, p. 233, pl. 9, figs. 1-3) to which it is 

 closely allied by the following characters : 



1. Antero-dorsal angle is nearly a right angle (decidedly 

 obtuse in Area satowi). 



2. Hinge-line is longer in comparison to shell-length than 

 in Area satowi. 



3. Number of ribs is thirty-eight to forty (thirty-five to 

 thirty-nine in Area satowi). 



4. Beaks less prominent. 



5. Beaks medially more deeply furrowed than in Area 

 satowi. 



6. Height, when compared to length, is less than in Area 

 satowi. 



Fossil occurrence. — Nagamrma Zone (Naganuma); Upper 

 Musashino of Musashi, Shimosa and Kazusa. 



Living. — Northern, Central and Western Japan; Philippines. 



» 



Genus Pecttniculus. Lamaeck. 



217. Pectunculus rotundus, Dunkeb. 



Pl. XVII. Figs. 10, 11. 



PecU nculus rotundus. Dunker, Index Moll. Mar. Jap., p. 236, pl. XVI, figs. 9, 10. Pilsbrt, 

 Cat. Mar. Moll. Jap., p. 150. 



Several specimens of a rotund Pectunculus flatly convex and 

 mostly small (below 25 millim. in diameter) in form. Dunker in 

 describing this species had a specimen only 22 millim. in diameter. 



