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IO27 



TERTIARY FAUNA OF FLORIDA 



slope fine, close, low imbrications ; hinge delicate, normal ; interior thickened 

 ray anteriorly not prominent, touched by the anterior end of the high pallial 

 sinus, which is wholly confluent below. Lon. 10.5, alt. 5, diam. 2.5 mm. 



The most common of the Chipola Telllnidce. The young are proportionately 

 longer and perceptibly flexed and rostrate behind, characters which lose their 

 prominence in the adults. From the following species this is distinguished 

 especially by its rather sparse concentric sculpture, giving the effect of T. alter- 

 nata Say in miniature. 



Tellina (Angulus) agria n. sp. 

 PLATE 46, FIGURE n. 



Oligocene sands of Oak Grove, Santa Rosa County, Florida ; Burns. 



Shell resembling the preceding species, but more slender and evenly covered 

 with close-set regular concentric threading ; beaks small, the minute protoconch 

 distinct, giving a pustular effect ; hinge normal, interior normal, the thickened 



ray present but ill defined, the pallial sinus as in T. acosmita. Lon. 6.7, alt. 



\ 

 3.5, diam. 2 mm. 



By its fine close striation this species recalls the recent T. sybaritica Dall, 

 which is a larger, more solid, and much more flexuous shell. 



Tellina (Angulus) acalypta n. sp. 

 PLATE 47, FIGURE 12. 



Oligocene of the Chipola horizon at Alum Bluff, Calhoun County, and in 

 Walton County, Florida; also in the Oak Grove sands, Santa Rosa County, 

 Florida; Burns. 



Shell small, polished, slightly inequivalve, inequilateral; anterior end 

 longer, rounded, posterior end produced, attenuated, obliquely truncate, ob- 

 tusely pointed ; beaks small, low, the disk near them smooth, polished ; surface 

 of the valve towards the margins with fine, regular, rather distant concentric 

 grooves, the posterior dorsal area with fine concentric wrinkles or smooth, the 

 shell showing traces of darker and lighter zones and obscure slightly depressed 

 rays ; valves moderately convex, the right slightly less so than the left ; hinge 

 normal, extremely fine and delicate; interior polished, thickened ray in left 

 valve present but feeble ; pallial sinus high, long, reaching the ray, and wholly 

 confluent below. Lon. 10.5, lat. 5.5, diam. 2.5 mm. 



This form is not unlike T. polita Say, but is a constantly less elevated shell. 



