TRANSACTIONS OF WAGNER 

 992 



TERTIARY FAUNA OF FLORIDA 



variable character in this group, and in the large series of recent specimens 

 in the National Collection there are several undoubted examples of this species 

 in which the pit is nearly as large as figured by Holmes. The color is also 

 variable and northern specimens, as usual, are less brilliant and have a thicker 

 periostracum. Quite young specimens are more transverse than those which 

 are older, and the adults differ somewhat in outline among themselves. 



Semele perlamellosa Heilprin. 

 Plate 37, Figures 4, 5. 

 Semele perlatnellosa Heilprin, Trans. Wagner Inst., i., pp. 92, I02, pi. 11, fig. 23, 1887. 



Pliocene of the Caloosahatchie and Shell Creek, Florida; Willcox and 

 Heilprin. 



The original figure of this elegant species was taken from an imperfect 

 specimen, and at Mr. Willcox's suggestion it has 'been refigured here from a 

 more perfect example. The dimensions of a well-preserved pair are : alt. 40, 

 Ion. 55, diam. 14 mm. 



Semele Leana n. sp. 

 Plate sy, Figures i, 2. 



Pliocene of the Caloosahatchie River and Shell Creek, Florida; Dall and 

 Willcox. 



Shell large, moderately inflated, somewhat inecjuilateral, the anterior end 

 longer, nearly equivalve ; anterior end evenly rounded, base evenly arcuate, 

 posterior end blunt, subtruncate, short ; lunule narrow, longer on the left valve, 

 the right valve-margin encroaching on the hinge-line in the lunular region ; 

 sculpture of feeble, flattened, small radial threads and numerous evenly dis- 

 tributed, rather high, concentric lamelL'e, those on the posterior dorsal areas 

 lower and forming an obtuse angle where they pass on to the disk; the edges 

 of the lamellae are more or less minutely crenulated by the radial sculpture; 

 hinge normal, pit rather large, pallial sinus large, rounded, ascending, free 

 from the pallial line except at junction. Lon. of average specimen 54, alt. 44, 

 diam. 18 mm. An exceptionally large valve measures lon. 63, alt. 52, diam. 

 (double) 22 mm. 



This extremely fine shell is of the same general type as 5". perlamellosa, but 

 of different outline and proportions, as the figures show very well. It is one 

 of the most characteristic shells of the Florida Pliocene and is not exactly 

 represented by any of the recent species of the coast so far discovered. It is 

 named in honor of the late Dr. Isaac Lea, one of the earliest, most careful and 

 thorough workers on our Tertiary Paleontology. 



