8 CONTENTS. 



Description of genera and species — Continued. Page. 



Micromitra Meek 332 



(Paterina) Beeclier 343 



(Iphidella) Walcott '. 359 



Volbortliia von Moller 365 



Helmersenia Pander. 367 



Curticia Walcott , 369 



Obolus Eichwald 370 



(Broggeria) Walcott ,. . 424 



(Palseobolus) Matthew 426 



(Fordinia) Walcott 428 



(Liugulobolus) Matthew 430 



(Mickwitzella) Walcott 434 



(Acritis) Volborth 437 



(Schmidtia) Volborth 441 



(Westonia) Walcott 450 



Lingulella Salter '. 468 



(Leptembolon) Mickwitz 541 



(Lingulepis) Hall 544 



Delgadella Walcott 560 



Elkania Ford 561 



Neobolus Waagen 564 



Bicia Walcott 568 



Dicellomus Hall 571 



Kutorgina Billings 579 



Schuchertina Walcott 585 



Obolella Billings 586 



(Glyptias) Walcott 599 



Botsfordia Matthew 601 



Schizopholis Waagen " 608 



Quebecia Walcott 609 



Yorkia Walcott ' 611 



Dearbornia Walcott 614 



Trematobolus Matthew , 615 



Schizambon Walcott 622 



Siphonotreta de Verneuil 624 



Keyserlingia Pander 628 



Acrothele Linnarsson 630 



(Redlichella) Walcott 662 



Discinolepis Waagen 664 



Linnarssonella Walcott 665 



Acrotreta Kutorga 671 



Acrothyra Matthew 715 



Discinopsis Matthew 720 



Orbiculoidea d 'Orbigny 722 



Philhedra Koken 724 



Nisusia Walcott 725 



(Jamesella) Walcott 731 



Protorthis Hall and Clarke 738 



(Loperia) Walcott ' 744 



Wimanella Walcott 745 



Billingsella Hall and Clarke 749 



Orusia Walcott 765 



Otusia Walcott 769 



Wynnia Walcott 771 



Eoorthis Walcott 772 



Finkelnburgia Walcott 793 



Eostrophomena Walcott ; .- 795 



Swantonia Walcott 796 



Syntrophia Hall and Clarke 798 



Huenella Walcott 805 



Clarkella Walcott 809 



