210 SYNOPSIS OF AMERICAN FOSSIL BUACHIOPODA. [iull 87. 



Derbya cymbula Hall uiul Clarke. Upper Carboiiilerous, 



Deih.vii cviiibuhi Hall iiud Clarke, Pal. New York, Mil, Pt. 1, 18'Jl.', i>. 348, pi. 



1115, iiys. 2, :i 

 Lor. Near Kau.sas City, Missouri. 



Derbya kaskaskiaensis (McCbosney). Kaskaskia (L. Garb,). 



Ortbis kaskaskioiisis McCliesiioy, Descriptions New Pal. Foss., IISW), p. ol. 

 Derbya kaskaskicnsis Hall and Clarke, Pal. New York, VIII, Pt. 1, 1892, pi. 



IIB, ii!>-. C^. 

 Loc. Kaskaskia, Chester, aud Critteuduii, Illiuois. 



Derbya keokiik Hall. Kuobstoiie- Keokuk (L. Carb.). 



Ortbis creuistria Y'aiidell and Sbuniard, Cout. Geol. Kentucky, 1847, pp. 10, 21. 

 Ortbis keokuk Hall, Geol. Survey Iowa, I, Pt. II, 1858, p. tUO, pi. 19, lig. 5.— 



Reyes, Geol. Survey Missouri, V, 1895, p. 63. 

 Streptorbyncbus keokuk Hall, Second Ann. I\e]>. New York State Geol., 1883, pi. 



41, figs. 1-3. 

 Streptorbyncbus crenistria AValcott, Mon. U. S. Geol. Survey, VIII, 1884, p. 279, 



pi. 18, tig. 14. 

 Derbya keokuk Hall and Clarke, Pal. New York, VIII, Pt. I, 1892, p. 2G2, pi. 11, 



ligs. 1-3. 

 Loc. Keokuk, Iowa; Warsaw and Nauvoo, Illinois; New Providence, Indiana; 



Clark County, Missouri ; Nevada. 



Derbya pratteni (McCbesiiey). Upper Carboniferous. 



Ortbis pratteni ^McC'besuuy, Descriptions New Pal. Fos.s., I860, p. 33. 

 Loc. Cbarbonier, Missouri. 



Derbya robusta (Hall). Uj)per Carboniferous 



Ortbis umbraculum? Owen (non Scblotb.), Geol. Survey Wisconsin, Iowa, Min 



nesota, 1852, pi. 5, lig. 11 (see specimens in U. S. Nat. Miis., Cat. Invert 



Foss., 17945). 

 Ortbis robusta Hall, Geol. Survey Iowa, I, Pt. II, 185S, p. 743, ]il. 28, tig. 5. 

 Streptorbyncbus robusta Hall, Second Ann. Iiep. New York State Geol., 1883 



pi. 40, iigs. 12-17. 

 Derbyia robusta Waagen, Pabeontologica Indica, Scr. XIII, 1, 18S4, p. 592. — Hal 



and Clarke, Pal. New York, VIII, Pt. I, 1892, p. 262, pi. 10, figs. 12-17; pi 



IIB, figs. 7, 8. 

 Loc. St. Clair County, Illinois. 



Derbya ruginosa Hall and Clarke. Keokuk (L. Carb.) 



Derbya ruginosa Hall and Clarke, Pal. New York, VIII, Pt. I, 1892, p. 346, pi 



llA, tigs. 25-27. 

 Loc. New Providence, Indiana. 



Dicellonius Hall=Obolella. 

 Dicelloinus crassa Hall = Obolella crassa. 

 Dicellonius polita Hall = ()bulella polita. 

 Dicctlosia Kiug=:Bilobite8, 

 Dicraniscus Meek = Triplecia. 

 Dicraiiiscus ortoiii Meek=Triplecia ortoui. 



DICTYONELLA Hall. Genotype Kliyuchonella! reticulata Hall 



Dictyonella Hall, Twentieth Rep. New York State Cab. Nat. Hist., 1867, p. 274 



Eicbwaldia Hall, Ibidem, 1867, pp. 274-277, witb figs. — Dall, American Jour 



Concb., VI, 1870, p. 98.— Hall and Clarke, Pal. New Y'ork, VIII, Pt. il, 1893 



p. 307 ;— Thirteenth Ann. Rep. New Y'ork State Geologist, 1895, p. 903. 



