- 254 - 



oa, opt evidently? did not -^-orEist on the Atlantio side,, although 

 luoiney and '"olTnes (1) notes its -nreseno . "^he hsrh^r of Ch!=)rles- 



ton. South Osrolina, an oocurrence 7,t:ich is discredited (2). 



(1). idem. 



(£). DaJJ. ..•• H., loc. Git., p. 778, 1898. 



'The radial sc "!._ jf the Bov.'den species is irregularly deve- 



loped, oome portions of the shell, especially the umbonal region, 

 rncy he smooth or the fine, swollen radial lines may cover the 

 entire surface. V/hen ^resent the;; are alw3,ys mor(= ^r less inter- 

 ri5.-ited. On one left valve these radials are especially r/ell de- 

 veloped, being more prominent than on any of the ty^oes. xinother 

 left valve, of whiSh only the ri-rr-:-T v-i-" -ip. -.-^reserved, has only 

 very faint concentric markings aaul the hinge "socket" is, strange- 

 ly enough, '"ithout the median distal raised triangular area. 



As stp-^'^d in -^iie ^-uoted dr p. n r -;_-,-. t ion, ] ithohletg -^ry iDe re- 

 cognized hy its radial sculpture. P« pi i cat a Tuoniey and Holmes 

 is a. smooth, marp-inally plicated form occurring in the -^uplin 

 formation of f'-e Oarolinas, 



Occurrence .- Lower I'liocene: Bov/den.heds, BoA'/den, Jamaica 

 (Ball, 1898). 



