104 PLEIOCENE FO.SSILS. 



PHOLAS M E M M I N G E E I . — {New Species.) 

 Plate XXIV. Pig. 6. 



P. testa oblongo-ovata, cylindrica, inflata, lineis elevatis, distantibus, laminatis, subdentatis 

 instructa; costis 6-8 ab apice ad marginem pallialem diver gentibus; costis anticis posticisque 

 obsoletis; margine anali tenui subtruncata, hiante; margine buccali crassa, laminata, acuta. 



Description. Shell oblong-ovate, cylindric, inflated; surface lines of growth irregu- 

 larly concentric, widely separated, coarsely laminated anteriorly; laminse with raised and 

 free edges, having a few elevated knobs or teeth, reflexed or folded on the anterior dorsal 

 margin, giving the shell an acute point on the buccal margin, and forming a laminated 

 umbonial shield, which extends from near the point to beyond the beak posteriorly and is 

 reflected upon the umbones, the inferior siirface of the upper plate divided by a few 

 indistinct almost obsolete transverse septa, which in some individuals are profoundly 

 obsolete; six or eight radiating ribs extend from the beak to the pallial margin, but they 

 become also profoundly obsolete towards the buccal and anal margins; anal margin thin, 

 sub-truncated gaping, its surface lines wrinkled and indistinct; buccal margin thick, 

 laminated, acutely pointed. 



This species may be easily distinguished from its congeners by its greater length from 

 beak to pallial margin, its laminated umhonial plates with small indistinct transverse 

 septa, and its raised laminated lines of growth having a few angulated knobs or teeth 

 which are destitute of arches; moreover, the buccal margin is thick and acutely pointed. 



By inscribing this fossil to the Hon. C. G. Memminger, the distinguished jurist, states- 

 man, and liberal patron of education, science and art, we take pleasure in connecting his 

 name with the rocks of his native State. 



Plate XXIV. Fig. 6, Left valve, natural size. The small transverse septa between the 

 superior umbonial plates are too indistinct to be given in the figure. 



Locality. Sumter District. 



Museum, College of Charleston. 



