356 



BRACHIOPODA. 



[ORB. ORT. 



— Obolus apolli- 

 6, Dorsal valve; 

 a, interior of ventral 

 valve. 



Fig. 

 nis 



canadensis, see Dinobolus canadensis. 



conradi, see Dinobolus conradi. 



galtensis, see Tri- 

 merella galten- 

 sis. 

 labradoricus, see 

 Kutorgina lab- 

 radorica. 

 (?) murrayi, Bill- 

 ings, 1865, Pal. 

 Fos8., vol. 1, p. 

 362, Quebec Gr. or Up. Taconic. 



pectinoides, Whitfield, 1875, Ludlow's Rep. 

 Black Hills of Dakota, p. 103, Up. 

 Taconic. 

 Orbicula, Cuvier, 1808, Tabe. Elem. d'Hist. 

 Nat., p. 435, syn. for Crania. 



cselata, see Lingulella ea-lata. 



cancellata, see Trematis cancellata. 



coirugata, see Crania corrugata. 



crat8a, see Obolella crassa. 



deformata, see Crania deformata. 



eccentrica, see Crania eccentrica. 



filota, see Schizocrania filosa. 



grandis, see Discina grandis. 



lamello8a,8ee Discina lamellosa. 



lodensis, see Discina lodeuwis. 



minuta, see Discina minuta. 



nitida, see Discina nitida. 



prima, see Crania prima. 



squamiformis, see Pholidops squamiformis. 



mbtruncata, see Pholidops subtruncatus. 



tenuilamellata , see, Discina tenuilauiellata. 

 * terminalis, see Trematis terminalis. 



inuicata, see Crania truncata. 

 Orhiculoidea, D'Orbigny, 1847, Comptes 

 rendus de l'Academie des Sciences, and 

 Prodr. de Paleont., t. 1, p. 44. [Ety. 

 Orbimla, a genus; aides, like.] Subor- 

 bicular, patelliform, longitudinally or 

 transversely oval, upper valve convex, 

 with vertex near the posterior margin ; 

 lower valve conical or concave ; no 

 pedicle disk ; a narrow oval or circular 

 aperture, more or less confined in its 

 shape, is situated in a furrow or depres- 

 sion. Type O. elliptica. 



conica, Dwight, 1880, Am. Jour. Sci. and 

 Arts, 3d ser., vol. 19, p. 452, Tren- 

 ton Gr. 

 Orthis, Dalman, 1827, Kongl. Vet. Acad. 

 Handl., p. 93. [Ety. orthos, straight, in 

 allusion to the straight hinge-line.] 

 Shell variable in form, hinge-line 

 straight; valves convex or plano-con- 

 vex, plicated, with or without mesial 

 fold and sinus ; cardinal area notched in 

 the center ; ventral valve with two 

 prominent diverging teeth, muscular 

 impression saucer-shaped, divided by a 

 median septum on which the central 

 adductor attached ; divaricator and ped- 

 icle impressions, lateral, fan-like; dor- 

 sal valve with a tooth-like, cardinal 

 process between two curved brachial 

 processes; adductor impression quad- 

 ruple; vascular impressions numerous, 

 spreading; no coiled spiral arms. Type 

 O. zonata and 0. callactis. 



acuminata, Billings, 1859, Can. Nat. Geo.. 



vol. 4, p. 440, Chazy Gr. 

 acutilirata, Conrad, 1842, (Delthyrisacnti- 



lirata,) Jour. Acad. Nat. Sci., vol. 8, p. 



280, Hud. Kiv. Gr. 

 acutiloba, liingueberg, 1888, Proe. Acad. 



Nat. Sci. Phil., p. 134, Niagara Gr. 

 requivalviB, Hall, 1847, Pal. N. Y., vol. 1, 



p. 120, Trenton (ir. 

 ;njnirdlva, Shaler. The name was pre- 

 occupied. 

 sequicahis, Hall, see Orthis eryna. 

 alata, Shaler. The name was preoccupied, 

 alsus, Hall, 1863, 16th Rep. N. Y. St. 



Mus. Nat. Hist., p. .".:!. Schoharie grit. 

 altemans, Casteluau, 1843, Syst. Sil., p. 



38. Not recognised. 

 amuma, Winchell, 1880, Geo. Sur. Minn. 



8th Rep., p. 65, Hud. Riv. Gr. 

 anticostiensis, syn. for Orthis porcata. 

 apicalis. Billings, 1865, Pal. Foss.. vol. 1, 



p. 301, Quebec Gr. 

 armanda, Billings, 1865, Pal. Foss.. vol. 1, 



p. 303, Quebec Ghr. 

 assimilis, Hall, 1859, Pal. N. Y., vol. 8, \>. 



175, Low. II. M. Gr. 

 aurelia, Billings, 1874, Pal. Foss., vol. 2, p. 



84, Gaspe limestone No. 8, Devonian. 

 barabuensis, see Lepta-na barabuensis. 

 battis, Billings, 1865, Pal. Foss., vol. 1, p. 



185, Quebec Gr. 

 bellarugosa, Conrad, 1843, Proc. Acad. 



Nat Sci. Phil., vol. l, p. :;:;:;, and Pal. 



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

 bellnla. Meek, 1873, Ohio Pal., vol. 1, p. 



103, Hud. Riv. Gr. 

 biforata, Schlotheim, 1820, (Terebratulites 



biforatos,) Petrefact., p. 265, Trenton 



and Hud. Riv. Grs. 

 billingsi, Hartt, 1868, Acad. GeoL, p. 844, 



St. John Gr. 

 biloba, Linna'iia, 1767, (Anomia bilobaj 



Linne, Syst., ed. 12, p. 1164, Niag- 

 ara < i r. 

 bilohata, Conrad, 1838, (Delthyrisbilobata,) 



Ann. Rep. N. Y. The name was pre- 

 occupied by Sowerby. 

 bisidcata, see Camarella bisulcata. 

 borealis, Billings, 1859, Can. Nat. Geo., 



vol. 4, p. 436, Chazy and Trenton (Irs. 

 carbonaria, Swallow, 1858, syn. for Orthis 



pecosi. 

 carinata, Hall, 1843, Geo. Rep. 4th Dist. 



N. Y., p. 267, and Pal. N. Y., vol. 4, p. 



58, Portage and Chemung Grs. 

 carleyi, Hall, svn. for Orthis retrorsa. 

 centrilineata, Hall, 1847, Pal. N. Y., vol. 



1, p. 289, Hud. Riv. Gr. 

 centrosa, n. sp., Hud. Riv. Gr. Proposed 



instead of O. crassa, in Cin. Quar. Jour. 



Sci., vol. 1, p. 20, and Ohio Pal., vol. 1, 



p. 117, pi. 10, fig. 3. 

 charlotte, Winchell, 1880, Geo. Sur. Minn., 



8th Rep., p. 67, Hud. Riv. Gr. 

 cincinnatieneis, S. A. Miller, 1883, 2d Ed. 



Am. Pal. Foss., p. 296, Hud. Riv. Gr., 



Cincinnati, Ohio. Proposed instead of 

 Orthis costata, Hall, 1845, Am. Jour. 



8ci. and Arts, vol. 48, p. 294. 



