80 



Fam. Productid^. 



Productus, Sovverby. 



Froducta, Sowerby, jr. 



Frodiicta, M'Coy. 



Frotonia, Link. 



* Fyxis, Chemnitz. 



Arbusculilcs, Murray. 



ArbuscuUthes, Paiitel. 

 Chonetes, Fischer. 



Lepfiiena, M'Coy. 



Chonetus, Paetel. 

 Productella, Plall. 

 Strophalosin, King. 



Slropholosia, Gray. 



Slophalosia, Bronn. 



Lcpiacnulosia, King. 



OrthotJirix, Geiuitz. 



Orithotlirix, Davidson. 



Orthotrix, auct. 

 Aulosteges, Helmersen. 



LYOPOMATA. 

 Fam. SiPHONOTRETiD^. 

 Sipbonotreta, Verneuil. 



Slplionotrema, Dana. 

 Mesotreta, Kiitorga. 

 Acrotreta, Kntorga. 

 Volbortbia, MiJller. 

 ? Eicbwaldia, Pillings. 

 ? Iphidea, Billings. 



Fam. Trimeuellid^. 



Trimerella, Billings. 



TrhneccUa, Paetel. 



Gotlandia, Dall. 



Fhynoholns, Hall. 



ObohUlna, Billings. 

 Dinobolns, Hall. 



UnguJL'es, Qneustedt. 



Conradia, Hall. 

 Monomere.lla, Billings. 

 ? Liugulops, Hall. 



Fam. OBOLiDiE. 

 Helmersen ia, Pander. 

 Keyserlingia, Pander. 

 ? Kutorgina, Billings (pars). 



Kurtngina, Davidson. 

 Monobolina, Salter. 

 Obolella, Billings. 

 ? Spondylobolus, M'Coy. 



Spondylobtis, Davidson. 

 Aulonotreta, Kntorga (pars). 



Leptobolus, Hall. 



Leptobulus, Hall. 



Aeritis, Volborth. 



Acrltea, Dav. & King. 

 Obolus, Eichwald. 



Obubts, Queustedt. 



Ungnla, Pander. 



Ungulifes, Bronn. 



Aulonotreta, sp. Kutorga. 

 (?) Schmidtia, Volborth, not Bals.-Criv. 



Dicellomus, Hall. 



Fam. LiNGULiD^. 



Dignomia, Hall. 



Lingnlella, Salter. 

 Lingnlepis, Hall. 

 Glottidia, Dall. 

 Glossiua, Phillips. 

 Lingula, Brugiere. 



Ligula, Cnvier. 



Ligularius, Dumeril. 



Lingulariiis, Herrmauusen. 



Fharetra, Bolten. 



Fam. DisciNiD^. 



Disciua, Lamarck. 



Orbiciila, Sowerby. 

 Discinisca, Dall. 

 Trematis, Sharj)e. 



Orbicella, D'Orbigny. 

 Orbiculoidea, D'Orbigny. 



Schizotrcta, Kutorga. 



Shizolreta, Davidson. 

 Schizocrania, Hall & Whitfield. 



Fam. Craniid^, 



Ci^auia, Retzius. 



* Criopodcrma, Poll. 



* Criopiderma, Poll. 

 Criopododerma, Agassi z. 

 Criopus, Gray. 

 Cr-yopus, Deshayes. 

 CranioVites, Schlotlieim. 

 CranioUtbes, auctt. 

 Discina, Turton. 

 *Xiintmiihis, Waller. 

 Nunmhis, Agassiz. 

 Orbh'ida, Cnvier. 

 Orbicidarius, Dumeril. 



Cran'scus, Dall. 

 Ancistrocrania, Dall. 



Cranopsis, Dall, not Adams. 

 Pseudocrania, M'Coy. 



Craniops, Hall. 



Pholidoiis, Hall. 



Falwocrania, Quenstedt. 

 Choniopora, Schauroth. 



