TRANSACTIONS OF WAGNER 

 II 38 



TERTIARY FAUNA OF FLORIDA 



Hindsiella carolinensis n. sp. 

 PLATE 45, FIGURE 4. 



Miocene of the Natural Well, Duplin County, North Carolina ; Burns. 



Shell small, rounded, moderately compressed, with low, inconspicuous beaks, 

 subequilateral, with a feeble mesial constriction ; sculpture of faint incremental 

 lines crossed by microscopic radial striation sometimes partly obsolete ; right 

 valve with a small stout subumbonal tooth, a resiliary scar behind the umbo, 

 and a faint groove in the posterior distal part of the narrow hinge-plate ; left 

 valve with two anterior teeth, the posterior one subumbonal and smaller, the 

 anterior hinge-plate excavated, the posterior with a narrow elongate resiliary 

 scar and a faint ridge representing the lamella ; interior of the valve polished 

 and faintly radially striate. Lon. 5.5, alt. 4.5, diam. 2.0 mm. 



The radial striae are only visible with a good light and strong magnifica- 

 tion. 



Hindsiella acuta n. sp. 

 PLATE 45, FIGURE 9. 



Miocene of the Natural Well, Duplin County, North Carolina; Burns. 



Shell small, cuneate, inflated, subequilateral, the posterior side broader and 

 rounded, the anterior narrower, more pointed and decurved ; anterior dorsal 

 margin declining, posterior arcuate ; middle of the base conspicuously insinu- 

 ate; surface sculptured with crowded, rather prominent, incremental lines, 

 feebler towards the anterior end, which shows some faint radial markings; 

 hinge-plate narrow, left valve with a prominent subumbonal tooth and a feeble 

 lamella a little in front of it, a strong resiliary scar, and a minute, obsolete, 

 very distant posterior lamella ; right valve with an arcuate, short, subumbonal 

 lamina, a deep pit for the opposite cardinal above it, and a short, distant, sharp 

 groove corresponding to the posterior lamella of the opposite valve; interior 

 of the valves polished, faintly radially striate, the adductor scars rather low 

 down. Lon. 6.0, alt. 4.0, diam. 3.0 mm. 



This species is especially characterized by its relatively acute anterior end. 

 which, in all the individual variations noted, is still preserved. 



It should be observed that, like nestlers in general, the species of Hind- 

 siella exhibit a good deal of variation among individuals; much more than 

 free bivalves usually show. Slight differences of outline count for little, but 

 there is always a certain fades which may serve as a sufficient guide in dis- 

 criminating one species from the others, provided one has a satisfactory amount 

 of material for study. 



