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definitely in linear series tovmrd the ventral maro-in, the series 

 separatee! by shallow grooves, an arrangement VThich is conoomitant 

 with the increase in size, as is shown hy the Sowden speciriiens. 

 The largest Anti??uaji V5lve, larger than any from Bowden, has a 

 na.rrow, scabrous medial rib in the intersoooes near the margin. 



Fo Pecten resembling theti ciis is known from the Bowdcn beds; 

 it differs from siimpleus by its more Inequilateral outline, higher, 

 sharper ribs, their eummits with a shallow sulcus, bounded by a 

 narroy/ radial on either side, vn.tla another rari.ial near the base, 

 the surface of the radials roughener? by irregular, lo?; elevations, 

 but not definite scales, along unequally spaced co;. centric lines. 



Occurrence .- U-TOer Oll.eocene: S nto Domingo ( oO ' .vl^.l'' - , ^TO ; 

 Gabb, 1873; Guopy, 1874, 1876; L'all , 1898); Anti.c-ua (Brown, 1917); 

 Curacao (l>all, 1898); lower Miocene: Bowden beds, Bov/den, 



Jamaica (C-uppy, 3866, 1874; D^'ll, 1398). 



