CLASSIFICATION. 323 



Oholus Eichwald [1829, p. 274]. 



(Broggeria) Walcott [1902, p. 605]. 



(Palseobolus) Matthew [1895b, p. 201]. 



(Fordinia) Walcott [1908d, p. 64]. 



{Lingulobolus) Matthew [1895b, p. 260]. 



{Mickwitzella) Walcott [1908d, p. 70]. 



{Acritis) Volborth [1869, p. 212]. 



(ScJimidtia) Volborth [1869, p. 208]. 



(Westonia) Walcott [1901, p. 683]. 

 Lingulella Salter [1866b, p. 333]. 



{Leptembolpn) Mickwitz [1896, p. 199]. 



(Lingulepis) Hall [1863, p: 129]. 

 Delgadella Walcott [1908e, pp. 142 and 144]. 



SubfamUy ELKAiraN.ffi Walcott and Schuchert [Walcott, 1908e, p. 144]. 



Divergent Obolidse with posterior or marginal (not central) platforms, to which are attached 

 the central and outside and middle lateral muscles. 

 ETkania Ford [1886b, p. 325]. 



Subfamily NEOBOLIN.!: Walcott and Schuchert [Walcott 1908e, p. 144]. 



Progressive Obolidse with posterior platforms, to which were probably attached ths central 

 and outside and middle lateral muscles. Subfamily apparently progressive from the Obolinse 

 to the Trimerellidse, though the platform is posterior and not subcentral as in the trimerelloids. 

 Neobolus Waagen [1885, p. 756]. 



Subfamily BICIIIT^ Walcott and Schuchert [Walcott, 1908e, p. 144J. 



Progressive Obolidse with the pedicle restricted to the ventral valve and more or less 

 inclosed by a pedicle tube, and with rudimentary articulation. The transgressing stock from 

 the Atremata to the Neotremata (Obolellidse) . 



Bicia Walcott [1901, p. 676]. 



Dicellomus Hall [1873, p. 246]. 



Superiamily KTJTOBGINACEA Walcott and Schuchert [Walcott, 1908e, p. 144]. 



Progressive, thick-shelled, almost calcareous atrematous-like shells, tending to be trans- 

 verse and developing rudimentary articulation, more or less rudimentary cardinal areas, pseu- 

 dodeltidia, and muscle scars prophetic of the Protremata. Derived out of Rustellacea. 



Family KirTOE,GIlIID.ffi; Schuchert [1893, p. 151]. 



(Emended Schuchert [1897, p. 131] and Walcott [1908e, p. 145].) 



Progressive transverse Kutorginacea with rudimentary cardinal areas, great delthyrial 

 opening, rudimentary articulation, and immature pseudodeltidia. Muscle scars prophetic of the 

 Strophomenacea. 



Kutorgina Billings [1861b, p. 9]. 



Family SCHirCHERTINID.ffi Walcott [1908e, p. 145]. 



Primitive round Kutorginacea with small cardinal areas. Externally like Oholus, with an 

 open subtriangular delthyrium which apparently is without a pseudodeltidium. Muscle scars 

 and vascular markings prophetic, through the BilhngselUdse, of the Strophomenacea. 

 Schuchertina Walcott [1905a, p. 323]. 



Order NEOTREMATA Beecher [1891, p. 354]. 



(Emended Schuchert [1897, p. 129] and Walcott [1908e, p. 145].) 



Derived and specialized inarticulate Brachiopoda (through the Obolidse of the Atremata), 



as a rule more phosphatic than calcareous, more or less cone-shaped, with the pedicle emerging 



during life through a perforation or sheath in the ventral valve, or a triangular more or less 



