BRACH10PODA. 



387 



dalli, Davidson & King, 1872, Brighton 

 Meeting Brit. Assoc., and Quar. Jour. 

 Geo. Soc., 1874, p. 154, Guelph Gr. 



galtensis, Billings, 

 1862, (Obolus 

 galtensis,) Pal. 

 Foss., vol. 1, p. 

 168, Guelph Gr. 

 grandis, Billings, 

 1862, Pal. Foss., 

 vol. 1, p. 166, 

 Guelph Gr. 

 minor, Ball, syn. for 



T. galtensis. 

 ohioensis, Meek, 

 1871, Am. Jour. 

 Sci., 2d series, 

 vol. 1, p. 315, and Ohio Pal., vol. 1, p. 

 183, Niagara Gr. 

 TRIPLESIA, Hall, 1858, 12th Rep. N. Y. 



FIG. 



633. Trimerella 

 galtensis. 



FIG. 634. Triplesia extans. 



Mus. Nat. Hist., p. 44. [Ety. triplasios, 

 thrice ; in allusion to the trilobate 

 character of the shell.] Shell trans- 

 verse or elongate, trilobate or subtri- 

 lobate ; ventral valve deeply sinuous 

 and dorsal, having a corresponding 

 fold ; hinge-line straight ; area small ; 

 foramen triangular; surface concen- 

 trically striated ; ventral valve with a 

 strong tooth on each side of the fissure ; 

 muscular impressions small ; dorsal 

 valve with a prominent bifurcating 

 cardinal process, on each side of 

 which there is a brachial process di- 

 rected obliquely inward and laterally. 

 Type T. extans. 



congesta, Conrad, 1842, ( Atrypa congesta,) 

 Jour. Acad. Nat. Sci., vol. 8, p. 265, and 

 Pal. N. Y., vol. 2, p. 67, Clinton Gr. 



cuspid ata,. Hall, 1847, (Atrypa cuspidata,) 

 Pal. N. Y., vol. 1, p. 138, Trenton Gr. 



nucleus, Hall, 1847, (Atrypa nucleus,) Pal. 

 N. Y., vol. 1, p. 138, Trenton Gr. 



ortoni, Meek, 1872, (Dicraniscus ortoni,) 

 Am. Jour. Sci. and Arts, 3d ser., vol. 4, 

 p. 280, and Ohio Pal., vol. 1, p. 178, 

 Niagara Gr. 



primordialis, Whitfield, 1878, Ann. Rep. 

 Geo. Sur. Wis., p. 51, and Geo. Wis., 

 vol. 4, p. 172, Potsdam Gr. 



putillus, Hall, syn. for T. waldronensis. 



radiata, Whitfield, 1889, Bull. Am. Mus. 

 Nat. Hist., vol. 2, p. 43, Calciferous Gr. 



waldronensis, Miller & Dyer, 1878, (Spirif- 

 era ? waldronensis,) Jour. Cin. Soc. 

 Nat. Hist., vol. 1, p. 37, Niagara Gr. 

 TROPIDOLEPTUS, Hall, 1857, proposed in 10th 

 Rep., but described in 1859 in 12th 

 Rep. N. Y. Mus. Nat. Hist., p. 31. [Ety. 

 tropis, the keel or bottom of a ship; 

 leptos, slender.] General form of Stro- 

 phomena ; surface plicated ; structure 

 punctate ; ventral valve convex, with 

 an area and wide fissure beneath the 

 beak ; dental lamellae distinct from the 

 margin of the fissure, crenulate; dorsal 

 valve concave, with crenulate dental 

 fossets ; a strong, cardinal process, with 

 diverging lobes in the interior, which 

 support slender crura that converge to 

 and unite with the median crest. Type 

 T. carinatus. 



FIG. 635. Triplesia ortoni. 



extans, Emmons, 1842, (Atrypa extans,) 

 Geo. Rep. 2d Dist. N. Y., p. 395, and 

 Pal. N. Y., vol. 1, p. 137, Trenton Gr. 



lateralis, Whitfield, 1886, Bull. Am. Mus. 

 Nat. Hist., vol. 1, p. 303, Birdseye Gr. 



FIG. 636. Tropidoleptus carinatus. 



carinatus, Conrad, 1839, (Strophomena 

 carinata.) Ann. Geo. Rep. N. Y., p. 64, 

 and Pal. N. Y., vol. 4, p. 407, Ham. Gr. 

 occidens, Hall, 1860, 13th Rep. N. Y. 

 Mus. Nat. Hist., p. 91, and Pal. N. Y., 

 vol. 4, p. 408, Ham. Gr. - 

 VITULINA, Hall, 1860, 13th Rep. N. Y. Mus. 

 Nat. Hist., p. 72. [Ety. mythological 

 name.] Externally it is 

 like Leptocoelia, but dis- 

 tinguished by its strong 

 dental lamellae and pro- 

 cesses. Type V. pustulosa. 

 pustulosa, Hall, 1860, 13th 

 Rep. N. Y. Mus. Nat. Hist., 

 p. 72, and Pal. N. Y., vol. 

 4, p. 410, Tully limestone. 

 WALDHEIMIA, King, 1849, Mon- 

 ograph of Permian Fossils, 

 p. 145. [Ety. proper 

 name.] Shell circular, sub- 

 quadrate, transverse or 

 elongated ; valves unequally convex, 

 smooth, or plicated ; beak truncated, 

 perforated ; deltidium in one or two 

 pieces ; loop long, formed of lamellae 

 attached by the crura to the hinge 



