TRANSACTIONS OF WAGNER 



TERTIARY FAUNA OF FLORIDA 



Section Chamelea Morch. 



Chione (? Chamelea) craspedonia n. sp. 



PLATE 55, FIGURE 2. 



Lower Oligocene of Vicksburg and Eocene of Red Bluff, Mississippi ; 

 Burns, Schuchert, and Johnson. 



Shell short-ovate or rounded-trigonal, inequilateral, the beaks nearly 

 smooth, low, prosogyrate, situated slightly behind the anterior third ; lunule 

 cordate, sharply defined by an incised line, not impressed, nearly smooth ; 

 escutcheon elongate, sharply defined by a keel which is more pronounced on 

 the left valve ; surface sculptured with small, regular, even concentric lamellae, 

 separated by wider interspaces which are concentrically striated ; the lamellae 

 on the anterior two-thirds of the shell frequently show obsolete cross-striation 

 which does not affect the interspaces ; anterior slope nearly straight, posterior 

 slope somewhat convex, ends rounded, base convexly arcuate ; hinge well de- 

 veloped, the larger cardinals sometimes faintly grooved ; adductor scars nearly 

 equal ; pallial sinus small, angular ; basal and anterior margins minutely crenu- 

 late. Length 28, height 24, diameter 14 mm. 



I thought at first that this attractive species might be referred to Chione 

 s. s., but finally decided to put it in this section with a mark of doubt. It is 

 certainly on the border line between the two sections. There is some variation 

 in the closeness of the lamellation, though very little in the general form. The 

 figure given by Conrad of the Chione mississippiensis is so remarkably dif- 

 ferent in outline that, unless Conrad's type was entirely abnormal, no question 

 of their identity could arise. 



Chione (Chamelea) nuciformis Heilprin. 



PLATE 55, FIGURE 9. 

 Cytherca nuciformis Heilprin, Trans. Wagner Inst., i., p. 116, pi. xvi., fig. 61, 1887. 



Oligocene silex beds of Ballast Point, Tampa Bay, Florida ; J. Shepard and 

 A. Heilprin. 



The original shell was so very poorly figured that it seemed desirable to 

 illustrate it. It very much resembles the following species in the character of 

 the sculpture and the form and size of the lunule, beaks, and ligament as well 

 as the internal characters. It differs in the following particulars : the beaks 

 are on the average higher, the escutcheon is sharply striated and not distinctly 

 differentiated from the rest of the surface, while in the next species the area 

 is marked off by a distinct keel within which, in the left valve, the escutcheon 



