86 



Tabic showing approximatehj the Inoiim distribution of the chief groups of Brachiopoda in 



geological time — Coutiuued. 



Productus, Sowerby. 

 Productella, Hall . , 

 Aulosteges, Ilelmersen . 



SirHOXOTEETID^. . . 

 Acrotreta, Kutorga . 

 Si^honotreta, Verneuil . 

 Mesotreta, Kutorga . . 

 Yolhorthia, Moller . . 



Tkimeeellid^ . . 

 Trimerella, Billings 

 Dinobolus, Hall . . 

 Monomerella, Billings 

 ? Lingulops, Hall . 



Obolid^e 



Spondylobolus, M'Coy . . . 

 Monobolina, Salter . . . . 

 Kutorgina, Billings . . . 

 Obolella, Billings . . . . 

 Obolus, Eichwald . . . . 

 Aulonotreta, Kutorga (pars). 

 Helmersenia, Pander . . . 

 Kcyserlingia, Pander . . . 

 Dicellomus, Hall . . . . 



LlNGULID^ . . 

 LingulcUa, Salter 

 Lingulepis, Hall . 

 Glossina, Phillips 

 Lingula, Brngiere 

 Dignomia, Hall . 

 Glottldia, Dall . 



DiSClNIDiE 



Discinisca, Dall 



Schizocrania. Hall & Whitfield 



