354 



BRACHIOPODA. 



[MER. MON. 



FIG. 582. Meristella 

 circe. Showing re- 

 mains of spiral ap- 

 pendages in the 

 dorsal valve. 



recurving upon themselves, are re- 

 united laterally. Type M. Isevis. 



arcuata, Hall, 1857, 

 (Merista arcuata,) 

 10th Rep. N. Y. St. 

 Mus. Nat. Hist, p. 

 95, and Pal. N. Y., 

 vol. 3, p. 249, Low. 

 Held. Gr. 



barrisi, Hall, 1860, 

 13th Rep. N. Y. St. 

 Mus. Nat Hist, p. 

 84, and Pal. N. Y., 

 vol. 4, p. 304, Mar- 

 cell us shale and 

 Ham. Gr. 



circe, Billings, 1861, 

 ,'Charionella circe,) 

 Can. Jour., vol. 6, 

 p. 273, Up. Held. 

 Gr. 



cylindrica, Hall, 1852, (Atrypa cylin- 

 drica.) Pal. N. Y., vol. 2, p. 76, Clinton 

 and Niagara Gr. 



doris, 1860, Hall, 13th Rep. N. Y. St. 

 Mus. Nat. Hist., p. 84, and Pal. N. Y., 

 vol. 4, p. 303, Schoharie grit and Cor- 

 niferous Gr. 



elissa, syn. for Meristella nasuta. 

 haskinsi, Hall, 1860, 13th Rep. N. Y. St. 

 Mus. Nat. Hist, p. 84, and Pal. N. Y., 

 vol. 4, p. 306, Ham. Gr. 

 (?) hyale, Billings, 1862, (Charionella 

 (?) hyale,) Pal. Foss., vol. 1, p. 166, 

 Guelph Gr. 

 julia, Billings, 1862, (Athyris Julia,) Pal. 



Fpss., vol. 1, p. 146, Mid. Sil. 



laevis, Yaauxem, 1843, (Atrypa leevis,) 



Geo. Rep. 3d Dist. N. Y., p. 120, and 



Pal. N. Y., vol. 3, p. 247, Low Held. Gr. 



lenta, Hall, 1867, Pal. N. Y., vol. 4, p. 420, 



Oriskany sandstone. 

 maria, see Whitfieldia maria. 

 meta, Hall, 1867, Pal. N. Y., vol. 4, p. 308, 



Ham. Gr. 



nasuta, Conrad, 1840, (Atrypa nasuta,) 

 Ann. Rep. N. Y., p. 18, and Pal. N. Y., 

 vol. 4, p. 299, Schoharie grit, Up. Held, 

 and Ham. Gr. 



princepp, Hall, 1857, (Merista princeps,) 

 10th Rep. N. Y. St. Mus. Nat Hist, p. 

 95, and Pal. N. Y., vol. 3, p. 252, Low. 

 Held. Gr. 



prinstana, Billings, 1862, (Athyris prins- 



tana,) Pal. Foss., vol. 1, p. 145, Mid. Sil. 



rectirostra, Hall, 1879, Desc. New Spec. 



Foss., p. 15, and llth Rep. Geo. and 



Nat. Hist. Ind., p. 301, Niagara Gr. 



rostrata, Hall, 1843,(Atrypa 



rostrata,) Geo. Rep. 4th 



Dist. N. Y., p. 202, and 



Pal. N. Y., vol. 4, p. 307, 



Ham. (ir. and Tully 



limestone. 



scitula, Hall, 1843, (Al 



scitula,) Geo. 4th Dist. Hide view. 

 N. Y., p. 171, and Pal. 

 N.Y., vol. 4, p. 302, Corniferous Gr. 1 lall 

 regards M. circe as a syn. for this species. 



unisulcata, Conrad, 1841, (Atrypa uni- 

 sulcata,) Ann. Rep. N. Y., p. 56, and 

 Pal. N. Y., vol. 4, p. 309, Up. Held, and 

 Ham. Gr. 



MERISTINA, Hall, 1867, 20th Rep. N. Y. St. 

 Mus. Nat Hist., p. 186, and Pal. N. Y., 

 vol. 4, p. 299. [Ety. Merista, a genus ; 

 inus, implying resemblance.] General 

 form like Meristella ; apex perforated ; 

 lamellae of the spires united by a sim- 

 ple loop ; spirals oval, and each con- 

 tains about nine convolutions ; the 

 two principal stems attach to the hinge 

 plate and extend into the interior be- 

 tween the spirals, where they bend 

 backward and give forth converging 

 lamelke, which cross between the spirals 

 to the ventral side, where they unite in 

 an angular point Type M. nitida. 

 nitida, Hall, 1843, 

 (Atrypa nitida,) 

 Geo. Rep. 4th 

 Dist. N. Y., pi. 14, 

 and Pal. N. Y., vol. 



2, p. 268, Niagara 

 Gr. 



nitida var. oblata, 

 Hall, 1852, (Atrypa 

 nitida var. oblata,) FlG . 584. _ Meristina 

 Pal. N. Y., vol. 2, p. nitida. Dorsal 

 269, Niagara Gr. vlew - 



MONOMERELLA, Billings, 1871, Can. Nat. and 

 Geo., vol. 6, p. 220. [Ety. monos, one ; 

 meros, a part ; ella, diminutive termina- 

 tion.] Shell thick, circular or trans- 

 versely oval in its marginal outline; 

 umbo of the pedicle, valve large, pro- 

 jecting, double-chambered ; area and 

 deltidium large ; hinge thick, elevated, 

 ledge-shaped, concave in the middle 

 portion ; cardinal facet a wall-like 

 space behind the ledge or flat of the 

 hinge; cardinal buttress strong, la- 

 melliform ; platform flat, slightly ele- 

 vated, widest, highest, and obtusely 

 angulated in front; umbo of the 

 brachial valve rounded ; hinge moder- 

 ately thick; platform trilobed; usually 

 with a thin margin. Type M. prisca.' 

 newberry i, 

 Hall & 

 Whitfield, 

 1875,Ohio, 

 Pal., vol. 

 2, p. 131, 

 Niagara 

 Gr. 



orbiculari s , 

 Bill ings , 

 1871, Can. 

 Nat, vol. 

 6, p. 220, 

 Guelph Gr. 

 ovata, Whiteaves, 1884, Pal. -Foss., vol. 



3, p. 5, Guelph Gr. 



ovata var. lata, Whiteaves, 1884, Pal. 



Foss., vol. 3, p. 6, Guelph Gr. 

 prisca, Billings, 1871, Can. Nat. and Geol., 



vol. 6, p. 220, Guelph Gr. 



FIG. 583. Mouomerella prisca. 



