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TERTIARY FAUNA OF FLORIDA ^^ 



Macoma (Psammacoma) brevifrons Say. 



Tellina brevifrons Say, Am. Conch., pi. Ixiv., fig. i, 1834; Binney's Say, p. 227, 1858; 



Hanley, Thes. Conch., i., p. 329, 1846; Tryon, Am. Mar. Conch., p. 149, pi. 26, figs. 



3SS-7 (bad), 1874. 

 fTellina oblonga Gmelin, Syst. Nat., p. 3234, 1792, after Chemnitz, Conch. Cab., vi., pi. 



ID, fig. 87. 



Pliocene of the Caloosahatchie marls, Monroe County, Florida ; Dall ; 

 recent from South Carolina to Brazil. 



This species, having been badly figured and the figures very erroneously 

 colored (having appeared after Mr. Say's death), seems to have been a good 

 deal confused. It resembles the preceding species a good deal, but is a shorter 

 and broader shell, usually small towards the northern extreme of its range 

 but attaining a considerable size (Ion. 39, alt. 23.5, diam. 13 mm.) in the 

 warmer waters southward and in the Pliocene. The recent specimens have 

 usually a blush of orange color in the central and umbonal region. T. hisoria, 

 which has been more or less confused with this species, I suspect to have been 

 founded on a large specimen of Macoma tenia. 



Macoma (Psammacoma) tageliformis n. sp. 



Pleistocene of Texas coast at Corpus Christi, and recent in the same 

 region but apparently rare. 



Shell rather thin, elongate, slightly flexuous, similar to the preceding 

 species in general form but more elongated, more rudely striated, more equi- 

 lateral, and, when living, without the orange suffusion ; pallial sinus discrepant 

 in the two valves ; in the left valve short, high, rounded above and behind, 

 half confluent with the pallial line below ; in M. brevifrons this sinus is an- 

 gular above and reaches nearer to the anterior adductor in front ; in the right 

 valve the sinus rises to a blunted angle in front of the posterior adductor 

 scar and close to it, then descends obliquely, and then returns to the pallial 

 line, with which it is less than half confluent ; this sinus is even shorter than 

 that in the opposite valve, while the same in brevifrons is one-fourth longer. 

 Lon. of shell 45, alt. 25, diam. 12.5 mm. 



This species, which, by its larger size, more elongate and flexuous form, 

 its absence of color, and its different pallial sinus, is well distinguished from 

 M. brevifrons, will be figured from the recent specimens in a forthcoming 

 report on the Mollusks of Porto Rico. 



