- 94 - 



low and eloiogate, \vhile others are hig-her and shorter. There is also 

 considerable variation in the araoixnt ^f inflation- some of the 

 lare-est individuals being much more inflated than the tj-pical form. 

 Relative excess of inflation is concomitant ".vith e:Kaessive height and 

 a less flattened posterior slope. The radial ribs may be flat and 

 feebly sculptured, instead of rou;:ded and sharply chiseled. Oc- 

 casionally the ribs are dichotomous and in the region in line vAfh 

 the narrow byssal gape, where the ribs are very narrow, secondary 

 even narrower ribs are often present. There is such a profusion 

 of individuals that it seems necessary to assume that the largest 

 specimens are actually adult. 



A, herryi is mtich smaller than any associated true Areas. 

 From the young of bov/deniana . occidental! s and u mbonata it differs 

 by the absence of a sharp, Vv^ell-defined posterior ridp-e, as v/ell 

 as in shape and sculpture. A, ( Scapharca) donacia is of about 

 the same size or slightly smaller, but, besid^-^s the obvious dif- 

 ferences that place the tv70 in separate subgenera, the one is 

 donaciform and the other trapezoidal. 



This species is named for Prof. 3. IV. Berrj^, of the Johns 

 Hopkins University, v/hose work has added greatly to the knowledge 

 of the Atlantic and Gulf Ooastal Plains. 



Occurrence .- lower Miocene ; Bowden beds, Bowden, Jamaica, 



