FREE INSTITUTE OF SCIENCE 



789 

 TERTIARY FAUNA OF FLORIDA 



Mytilus (Hormomya) hamatus Say. 



/ Mytilus >;-cur-,'iis Rat'., Mon. Coq. Biv. Ohio, p. 55, 1820; New Orleans. 

 Mylilns hiiiiiiitiis Say, Journ. Acad. Nat. Sci. Phila., ii., p. 265, 1822 ; Binney's reprint of 



Say, pp. 91, 204, pi. 50; Dall, Bull. U. S. Nat. Mus. No. 37, p. 38, 1889. 

 /!i;ti-/i\'ii<>iiti-s /taiiiati/s Perkins, Proc. Bost. Soc. Nat. Hist., xiii., p. 156, 1869. 

 .' l)n-issciiit ivcurva Fischer, Journ. de Conchyl., vii., p. 130, 1858. 

 .Mytillns slrialits Barnes, Am. Journ. Sci., vi., p. 364, 1823 ; Say, Am. Conch., v., pi. 50, 



1832- 

 Mitdiola haniatus Verrill, Am. Journ. Sci., 3d Ser., iii., p. 21 1, pi. 7, fig. 3, 1872; Inv. 



An. Vineyard Sound, p. 693, 1873. 

 Mytilus itini/iiti-nsis Conrad, Journ. Acad. Nat. Sci. Phila., vii., p. 244, pi. 20, fig. 6, 



1837; Tryon, Am. Mar. Conch., p. 187, fig. 513, 1874. 



Pliocene of the Caloosahatchie, Dall ; Pleistocene of VVailes Bluff, St. 

 Mary's County, Maryland, Burns ; recent from Long Island Sound south to 

 Costa Rica. 



On the Pacific coast, besides M. cdtdis, the Pleistocene affords the great 

 M. calif or nia mis Conrad, which even, according to Cooper, is found in the 

 Pliocene, and M. pcdroanns Conrad, which is perhaps identical with M. edulis. 

 The Pliocene affords M. Middcndorfii Grewingk (Beitr. Kenntn. N. W. Kuste 

 Am., p. 360, pi. vii., figs. 3 a-c, 1850) and M. Condom Dall (Nautilus, iv., p. 87, 

 Dec., 1890), peculiar species with a few broad plications posteriorly, from 

 Alaska and Oregon respectively. In the Miocene are the large M. Matliew- 

 soni Gabb and the M. incrjcnsis of Conrad, which may prove to be the same \y- 

 as Modiola inultiradiala Gabb ; both are radiately sculptured and of rather 

 uncertain outline. In the Eocene (Tejon) are M. ascia Gabb and M. httiitenis 

 Conrad, both rather obscure, smooth species, and M. (Ilorinoinya) dichotomns 

 Cooper (Bull. Cal. State Mining Bureau, No. 4, p. 49, pi. v., fig. 64, 1894), of 

 which the characters, even the genus, arc imperfectly known. Its relations to 

 Scptifcr dichotomies Gabb and 5". bifurcatus Reeve, as well as Mytilus bifurcatus 

 (Conr.) Stearns, remain to be clearly made out. 



Subgenus MYTILOCONCHA Conrad. 

 Myocuncliti Conrad, Medial Tcrt., p. 52, 1840. 



Myli/,i,-i'iu-/in Conrad, Proc. Acad. Nat. Sci. Phila. for 1862, p. 2yo, 1862. 

 i Conrad, op. fit., p. 578, 1863. 



Mytilus (Mytiloconcha) incurvus Conrad. 

 incitnui Conrad, Medial Tert., No. I, p. 3 of cover, 1839; No. 2, p. 52, pi. 



28, fig. I, 1840. 



