DEL. DIN.] 



BRACHIOPODA. 



343 



billingsi, Meek, 1868, Trans. Chi. Acad. 



Sci., p. 97, Ham. Gr. 

 biplicata, Hall, 1857, (Cyrtia biplicata,) 



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



165, Schoharie grit and Cornif. Gr. 

 crassa, Hall, 1867, Pal. N. Y., vol. 4, p. 



267, Up. Held. Gr. 

 curvilineata, White, 1865, (Cyrtia cur<ri- 



Hneata,) Proc. Bost. Soc. Nat. Hist., 



vol. 9, p. 25, and Pal. N. Y., vol. 4, p. 



270, Ham. Gr. 

 dalmani, Hall, 1857, (Cyrtia dalmani,) 



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



64, Low. Held. Gr. 

 davidsoni, Walcott, 1885, Monogr. U. S. 



Geo. Sur., vol. 8, p. 146, Devonian, 

 euphemia, Billings, 1863, Can. Nat. and 



Geol., vol. 8, p. 19, Corniferous Gr. 



FIG. 558. Cyrtina hamiltonensis. Dorsal, veii- 

 iral, and side views. 



hamiltonensis, Hall, 1857, (Cyrtia hamil- 

 tonensis,) 10th Rep. N. Y. St. Mus. Nat. 

 Hist,, p. 166, and Pal. N. Y., vol. 4, p. 

 268, Schoharie grit, Cornif. and 

 Ham. Grs. 



hamiltonensis var. recta, Hall, 1867, Pal. 

 N. Y., vol. 4, p. 270, Ham. Gr. 



missouriensis, Swallow, 1860, (Cyrtia mis- 

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

 vol. 1, p. 647, Ham. Gr. 



occidentalis, Swallow, 1860, (Cyrtia occi- 

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

 vol. 1, p. 648, Ham. Gr. 



panda, Meek, 1868, Trans. Chi. Acad. Sci., 

 p. 100, Ham. Gr. 



pyramidalis, Hall, 1852, (Spirifer pyra- 

 midalis,) Pal. N. Y., vol. 2, p. 266, Niag- 

 ara Gr. 



rostrata, Hall, 1857, (Cyrtiarostrata,) 10th 

 Rep. N. Y. St. Mus. Nat. Hist., p. 64, 

 Oriskany sandstone. 



triquetra, Hall, 1858, (Cyrtia triquetra,) 

 Geo. Rep. Iowa, vol. 1, pt. 2, p. 513, 

 Ham. Gr. 



umbonata, Hall, 1858, (Cyrtia umbonata,) 

 Geo. Rep. Iowa, vol. 1, pt. 2, p. 512, 

 Ham. Gr. 

 Delthyris, Dalman, 1827, syn. for Spirifera. 



acanthoptera, syn. for Spirifera disjuncta. 



acuminata, Conrad, see Spirifera acumi- 

 nata. 



acuminata, Hall, syn. for Spirifera mesa- 

 costal is. 



acutilirata, see Orthis acutilirata. 



arenosa, see Spirifera arenosa. 



audacula, see Spirifera audacula. 



bialveata, see Spirifera bialveata. 



bilobata, see Orthis bilobata. 



brachynota, see Spirifera brachynota. 



chemungensis, syn. for Spirifera disjuncta. 



congeta, see Spirifera cpngesta. 



cuspidala, syn. for Spirifera disjuncta. 



decemplicata, see Spirifera decemplicata. 



deltoidea, syn. for Orthis lynx. 



disjuncla, see Spirifera disjuncta. 



duodenaria, see Spirifera duodenaria. 



dupliplicata, see Spirifera dupliplicata. 



euruteines, see Spirifera euruteines. 



expansa, see Pterotheca expansa. 



fimbriata, see Spirifera fimbriata. 



granulifera, see Spirifera granulifera. 



granulosa, see Spirifera granulosa. 



inermis, see Spirifera disjuncta. 



laevis, see Spirifera leevis. 



mctcronota, see Spirifera macronota. 



macropleura, see Spirifera macropleura. 



medialis, see Spirifera medialis. 



mesacoslalis, see Spirifera mesacostalis. 



mesastrialis, see Spirifera mesastrialis. 



microptera, syn. for Orthis lynx. 



mucronuta, see Spirifera mucronata. 



niagarensis, see Spirifera niagarensis. 



pachyptera, see Spirifera pachyptera. 



perlata, see Spirifera disjuncta. 



prolata, see Spirifera prolata. 



prora, see Spirifera prora. 



radiata, see Spirifera radiate. 



raricoista, see Spirifera raricosta. 



rugoiina, see Spirifera rugatina. 



sculptilis, see Spirifera sculptilis. 



staminea, see Spirifera staminea. 



triloba, see Spirifera triloba. 



undulata, see Spirifera undulata. 



varica, see Orthis varica. 



ziczac, see Spirifera ziczac. 

 Dicellomus, Hall, 1873, 23d Rep. N. Y. St. 

 Mus. Nat. Hist., p. 246. Agenericname 

 proposed for the reception of Obolella 

 crassa and O. polita, without distin- 

 guishing the generic characters. 

 Dicraniscus, Meek, syn, for Triplesia. 



ortoni, see Triplesia ortoni. 

 DIGNOMIA. Hall, 1873, 23d Rep. N. Y. St. 

 Mus. Nat. Hist, p. 245. [Ety. di, from ; 

 dis, twice ; gnoma, a sign.] Lingula-like 

 shells having a longitudinal septum in 

 one or both valves. Type D. alveata 



alveata, Hall, 1873, 23d Rep. N. Y. St. 



Mus. Nat. Hist., p. 245, Ham. Gr. 

 DINOBOLUS, Hall, March, 1871, 23d Rep. 

 N. Y. St. Mus. Nat. Hist, p. 247. [Ety. 

 dis, twice; Obolus, a genus of shells.] 

 Shell subcircular, valves thick; umbo 

 of the ventral valve slightly prominent ; 

 area wider thau long; platform sin- 

 uated, widely V-shaped ; crescent prom- 

 inently marked in crown and sides; 

 hinge moderately thick, edge rounded, 

 with a pair of subcardinal scars in front 

 of the cardinal facet; umbo of the 

 brachial valve tumid ; platform trilobed ; 

 outer margins raised ; antemedian por- 

 tion rounded, projecting, and terminat- 

 ing in a median plate ; crescent a marked 

 linear scar on the hinge ; arching for- 

 ward in front of the cardinal facet; an 

 indentation on the inner border of its 

 sides near the hinge, another further 

 forward ; outer border a fine line ; sub- 

 cardinal scar in the umbonal cavity; 

 rhomboidal, postmediah scar in front of 

 the latter. Type D. conradi. 



