i62 Studies in Geology, No. 3 



sulcus is more prominent. It is also like T. cibaoica Maury 

 (loc. cit.), but is less inflated, shorter, has a more prominent 

 posterior sulcus, and the posterior margin is more blunt. 

 T. aequitcrminata Brown and Pilsbry,^*^ from Gatun, is also 

 similar, but differs much as it does from T. capotalensis. 

 T. singczvaldi and T. zapotalensis, being closely related, 

 have naturally the same general affinities. T. singezvaldi is 

 perhaps nearest to T. papyria Conrad,^^^ of the Claiborne 

 Eocene. Comparison with specimens of papyria from Lisbon 

 and Claiborne shows an agreement which is imperfect only 

 in the longer form of papyria. 

 Lower Zorritos. Quebrata Zapotal. 



Family PSAMMOBIIDAE 



Genus Tagelus Gray 

 Tagclus gibbus (Spengler) 



Solcn gibbus Spgl., Skrift. Nat. Selsk., vol. 3, p. 304, 1794. 



Solcn guinecnsis Chemn., Conch. Cab., vol. 11, p. 102, pi. 198, fig. 

 1937, 1795; Dilwyn, Descr. Cat., vol. i, p. 62, 1817; Wood, Gen. 

 Conch., p. 129, 1835. 



Solen decUvis Turton, Conch. Diet., p. 164, fig. 80, 1819. 



Psammobia decUvis Turton, Dithyra Brit., p. 91, 1822. 

 ■Solen caribaeus Lam. An. sans. Vert., vol. 5, p. 454, 1818. 



Siliquaria notata Schum. Essai, p. 129, pi. 7, figs. 2-3, 1817. 



Solecurtus caribaeus, Blainv., Diet. Sc. Nat., vol. 29, p. 240, 1825; 

 Conrad, Am. Mar. Conch., p. 22, pi. 4, fig. 3, 1831 ; Gould, Inv. 

 Mass., p. 30, 184 1 ; Mighels, Bost. Journ. Nat. Hist., vol. 4, p. 312, 

 184s; Sowerby, Conch. Icon., Solecurtus, fig. 21a, b, 1874. 



Solen adamsonii Bosc, Hist. Nat. Coq., vol. 3, p. 12, 1802. 



Cultellus caribaeus Conrad, Am. Jour. Sc, 2nd ser. vol. i, p. 404, 

 1846; not of Med. Tert., pi. 43. fig. i, 1845. 



Siliquaria gibba H. & A. Adams, Gen. Rec. Moll., vol. 2, p. 347, 

 not p. 93, figs. 5. 5a. 1856. 



'"' Proc. Ac. Nat. vSc. Phila.. vol. 64, p. 517. pl- 26, fig. 5, 1912. 

 '"" Harris, Bull. Amer. Pal., vol. 6. No. 31, p. 159. pl- 49, figs. 7-11, 

 1919. 



