(89) Galveston Well Fossils 7 



Area labiata Sowerby, var. PI. i, fig's i, la. 



Syn. A. labiata Har. , 4th Ann. Rep. Geol. Surv. Tex., 1893, 

 p. 121. 

 Area (small LimopsisASks.') Har., ibid. ; very 5^oung. 



The specimens derived from the well at Galveston are general- 

 ly small, though fragments of adults occur. The onh' difference 

 between these Miocene specimens and those now living on the 

 west coast of Mexico and Central America is that in the latter the 

 ligamental area in either valve is broader and more nearly isosce- 

 les-triangular in outline. Accordingly the beaks in the well spec- 

 imens are less distant and are twisted anteriorly. The corre- 

 spondence of this variety with an undescribed form from the 

 Pliocene of Alligator creek, Florida, is close. The well spec- 

 imens are doubtless ancestral to both later forms and hence par- 

 take somewhat of the nature of both. 



Range in depth. — From 2,510 to 2,871 feet. 



LED A. 

 Leda eoneentriea ? Sa}'. 



S5'n. L. eoneentriea Flar., 4th Ann. Rep. Geol. Surv., p. 121. 



There is no question as to the identit}^ of the two varietal forms in- 

 cluded under this name with specimens collected from the Gulf 

 shore and now included in the collection of the U. S. National 

 Museum. There is some doubt in the mind of the writer as to 

 whether all may properl}^ be called eoneentriea Sa}'. 



Range in depth. — From the surface to 2,650 feet. 



CRASSATELLA. 



Crassatella gibbesi T. and H., var. 



S^^n. C. gibbesi, var., Har., 4th Ann. Rep. Tex. Surv., 

 p. 121. 



Ball's C. floridana is evidently a variety of this species. It dif- 

 fers ixova. gibbesi in that {a) its posterior is less acute, ((5) its an- 

 terio-dorsal margin is slightly concave while in gibbesi it is con- 

 vex. For an excellent figure oi Jtoridana see Bull. U. S. Nation- 

 al Museum No. 37, pi. 42, fig. 4. 



The variety from the Galveston well is still further removed 

 irom floridana , its posterior being quite pointed. From gibbesi 

 it seems to differ in having the two anterior cardinal teeth in the 

 left valve less similar in size ; the more medially located tooth is 

 very small, and the lower border of the hinge plate curves slight- 



