TRANSACTIONS OF WAGNER 

 654 



TERTIARY FAUNA OF FLORIDA 



Pliocene of the Waccamaw beds of South Carolina ; and of the Caloosa- 

 hatchie, Shell Creek, Alligator Creek, and Myakka River, Florida ; WiUcox 

 and Ball. 



The collection of more material since Professor Heilprin's publication 

 leaves no doubt whatever as to the identity of this splendid species with that 

 of Tuomey and Holmes. It seems to be characteristic of the southern Plio- 

 cene. The beaks are much incurved and distinctly prosocoelous, the cardinal 

 area short and wide in front of them, long and narrow with much elevated 

 margins behind ; the anterior part of the area is transversely grooved at right 

 angles to the hinge-line; the posterior part has converging grooves, thus 

 forming three or four concentric triangles. The hinge is composed of a short 

 anterior and long posterior series of subequal vertical teeth vertically striated 

 on their flat surfaces; there are over forty teeth, of which twelve are anterior; 

 the two series are closely approximated. Many of the specimens have a 

 strong posterior auriculation which is more prominent in the young ; one 

 specimen measures thirty-two millimetres on the hinge-line and twenty-eight 

 millimetres below the auriculation. An adult measures fifty-three millimetres 

 long, thirty-six millimetres high, and forty millimetres in diameter. The 

 largest valve obtained is seventy-one millimetres long and has fifty-four 

 posterior and seventeen anterior teeth. In this specimen there are nine 

 longitudinal grooves, and the three or four middle ones are extended in 

 front of the beaks, contrary to the rule in younger specimens, giving the 

 grooved area as a whole the form of a long, narrow " stemmed" arrow-head. 

 In this valve the hinge-line is sixty millimetres long and the vertical of the 

 beak is ten millimetres from the anterior end. 



On the whole, this is one of the finest and most striking species in our 

 whole Tertiary fauna. The specimen figured is comparatively young. 



Scapharca (Anadara) catasarca n. s. 

 Plate 32, Figure 20. 



Pliocene marl of Alligator and Shell Creeks, Florida; Willcox. 



Shell elongate, solid, subrhomboidal, with very anterior, high, prosocoe- 

 lous beaks; right valve with twenty-three strong, narrow, rounded ribs, sepa- 

 rated by wider, very deep channelled interspaces ; concentric sculpture of 

 incremental lines, which are slightly elevated at regular intervals, and cause 

 over much of the valve the tops of the ribs to appear obscurely nodulous ; 

 the ribs on the anterior end, though simple in the young, are sharply mesially 



