BIBLIOGRAPHIC LIST OF GENERA AND SPECIES. 887 



Orthis armanda Billings. See Syntrophia? armanda. 

 Orthis (Plectorthis) atava Walcott. See Eoorthia atava. 

 Orthis barabuensis Winchell. See Syntrophia barabuensis. 

 Orthis Battis Billings. See Hebertella battis. 

 Orthis bellarugosa Conrad. See Hebertella bellarugosa. 

 Orthis bellarugosa Hall. See Hebertella insculpta. 

 Orthis bellula Meek. See Pianodema bellula. 



Orthis benedict! Miller. 



Orthis benedicti Miller, 17th Rep. State Geol. Indiana, 1891, p. 78, pi. 13, figs. 7-9. 

 Niagaran (Waldron): Hartsville, Indiana. 



Orthis bicostatus Vanuxem. See Reticularia bicostata. 



Orthis biforata Nicholson. See Platystrophia lynx. 



Orthis (Platystrophia) biforata Foerste. See Platystrophia daytonensis and P. 

 reversata. 



Orthis (Platystrophia) biforata var. acutilirata Lesley. See Platystrophia 

 acutilirata. 



Orthis (Platystrophia) biforata var. dentata Lesley. See Platystrophia crassa. 



Orthis (Platystrophia) biforata var. laticostata Lesley. See Platystrophia 

 laticosta. 



Orthis (Platystrophia) biforata var. lynx Meek. See Platystrophia lynx. 



Orthis biforata var. lynx forma daytonensis Foerste. See Platystrophia day- 

 tonensis. 



Orthis biforata var. lynx forma reversata Foerste. See Platystrophia reversata. 



Orthis biforatus Billings. See Platystrophia biforata. 



Orthis biloba Hall. See Bilobites bilobus. 



Orthis bisulcata Emmons. See Cyelospira bisulcata. 



Orthis borealis Meek. See Hebertella frankfortensis. 



Orthis borealis Billings. See Hebertella borealis. 



Orthis callactis amazonlca Clarke. 



Orthis callactis var. amazonica Clarke, Arch. Mus. Rio de Janeiro, 10, author's 



Engl, ed., June, 1900, p. 9, pi. 1, figs. 17-21. 

 Silurian: Rio Trombetas, Brazil. 



Orthis calligramma Kayser. 



Orthis calligramma Kayser (not Davidson), Palseontographica, Suppl. 3, 1876, 



pp. 18, 26, pi. 3, figs. 9-18. 

 Ordovician: Cordillere San Juan, Argentina. 



Observation. — These shells appear to be more closely related to O. plicatella 

 than to O. calligramma (Schuchert). 



Orthis calligramma Foerste. See Orthis flabellites. 



