MYT.] 



LAMELLIBRANCHIA TA. 



498 



angulata, Meek & Worthen, 1860, Proc. 



Acad. Nat. Sci. Phil., p. 455, and Geo. 



Sur. 111., vol. 2, p. 300, Kaskaskia Gr. 

 apachesi, Marcou, 1858, Geol. North 



America, p. 44, Subcarboniferous. 

 aviculoides, Meek & Hayden, 1860, Proc. 



Acad. Nat, Sci. Phil., p. 184, and Pal. 



Up. Mo., p. 51, Permian Gr. 

 aviculoides, Winchell, see M. rara. 

 concava, Swallow, 1858, (Mytilus con- 



cavus,) Trans. St. Louis Acad. Sci., vol. 



1, p. 188, Permian Gr. 

 concentrica, Meek & Worthen, 1860, Proc. 



Acad. Nat. Sci. Phil., p. 456, and Geo. 



Sur. 111., vol. 2, p. 281, Warsaw Gr. 

 congeneris, Walcott, 1885, U. S. Geo. Sur., 



vol. 8, p. 237. Subcarboniferous. 

 Cuneiforms, Gurley, 1883, New Garb. Foss., 



p. 4. Publication invalid, 

 deltoidea, Gabb, 1859, Proc. Acad.. Nat. 



Sci. Phil., p. 297, Subcarboniferous. 

 imbricaria, Winchell, 1862, Proc. Acad. 



Nat. Sci., p. 412, Marshall Gr. 

 iowensis, Winchell, 1865, Proc. Acad. 



Nat. Sci., p. 127, Chemung Gr. 

 kansasensis, Shumard, 1858, Trans. St. 



Louis Acad. Sci., vol. 1, p. 213, Coal 



Meas. 

 keokuk, Worthen, 1875, Geo. Sur. 111., vol. 



6, p. 524, Keokuk Gr. 

 meliniformis, Meek & Worthen, 1866, 



Proc. Chi. Acad. Sci., vol. 1, p. 19, Coal 



Meas. 

 michiganensis, Winchell, 1862, Proc. 



Acad. Nat. Sci., p. 411, Marshall Gr. 

 monroensis, Worthen, 1884, Bull. No. 2, 



111. St. Mus. Nat. Hist., p. 15, and 



Geo. Snr. 111., vol. 8, p. 127, St. 



Louis Gr. 

 mytiliformis, Hall, 1852, Pal. N. Y., vol. 



2, p. 100, Clinton Gr. 



nemesis, Walcott, 1885, Monogr. U. S. 

 Geo. Sur., vol. 8, p. 237, Subcarbonif- 

 erous. 



nessus, Walcott, 1885, Monogr. U. S. 

 Geo. Sur., vol. 8, p. 238, Subcarbonif- 

 erous. 



perattenuata, Meek & Hayden, 1858, 

 Trans. Alb- Inst., vol. 4, p. 77, and 

 Geo. Sur. 111., vol. 5, p. 582, Coal 

 Meas. 



permiana, Swallow, 1858, (Mytilus per- 

 mianus,) Trans. St. Louis Acad. Sci., 

 vol. 1, p. 187, and Pal. Up. Mo., p. 52, 

 Permian Gr. 



perniformis, Cox, 1857, Geo. Sur. Ky., 

 vol. 3, p. 569, Coal Meas. 



pterineiformis, Winchell, 1862, Proc. 

 Acad. Nat. Sci., p. 412, Marshall Gr. 



rara, Winchell, 1870, Proc. Am. Phil. 

 Soc., p. 390, Marshall Gr. Proposed 

 instead of M. aviculoides, Winchell, 

 1862, which was preoccupied. 



recta, Shumard, 1858, Trans. St. Louis 

 Acad. Sci., vol. 1, p. 212, Permian Gr. 



recurvirostris, Meek & Worthen, 1860, 

 Proc. Acad. Nat. Sci. Phil., p. 456, and 

 Geo. Sur. 111., vol. 2, p. 344, Up. Coal 

 Meas. 



squamosa, Sowerby, 1827, Trans. Geo. 



Soc. Lond., 2d ser., vol. 3, Permian Gr. 

 subquadrata, Shumard, 1855, Geo. Rep. 



Mo., p. 207, Coal Meas. 



FIG. 860. Myalina recurvirostris. 



stludovici, Worthen, 1873, Geo. Sur. 111., 



vol. 5, p. 540, St. Louis Gr. 

 swallovi, McChesney, 1860, New Pal. Foss., 



p. 57, and Geo. Sur. 111., vol. 2, p. 341, 



Coal Meas. 



FIG. 861. Myalina subquadrata. 



MYTILARCA, Hall, 1870, Prelim. Notice Lam. 

 Shells, p. 19. [Ety. from the two gen- 

 era Mytilus and Area.'] Equivalve, in- 

 equilateral, mytiliform ; beaks terminal; 

 hinge short; ligamental area stiiated; 

 cardinal teeth beneath the beak small, 

 oblique ; posterior teeth small, oblique, 

 and at the extremity of the hinge ; an- 

 terior muscular scar umbonal, and pos- 

 terior one near the postero-basal mar- 

 gin ; pallial line entire, simple ; f-urface 

 not unfrequently with fine, obscure ra- 

 diating striae. Type M. chemungensie. 



