- 61 - 



spaced only on the umbo and is almost obsolete in the region anter- 

 ior to the anterior sulcation; in addition the chondronhore is 

 placed well tuider the tmiho so that it is almost concealed when the 

 interior of the shell is viewed in norinal position. 



The " Leda "^f, acuta " v/hich Toala (l) described in his accoujit 

 of the "Pliocene" fauna of Tehuantepec differ from both acuta and 

 indjgena in having the posterior portion of the ventral margin 

 less convey and a straight er and blux.ter ros'':r\im. 



It may be added that Guppy's figure of bi sulcata is poor 

 and probably represents a yoimg, high indi^'ldual. 



(1). Jahrb. K.-k. geol. Reichsanstalt , vol. 61, p. 478, pi. 

 fig. 6, 1911. 



Occurrence .- ipy.^er Miocene: Bowden be^ls, 3ov;derL, Jamaica 

 (Guppy, 18 67, 1874; Dall, 1898). 



