I. 



THE GENERA OF THE PALEOZOIC BRACHIOPODA. 



[During the progress of the work preparatory for volume "VTII 

 of the Palaeontology of New York it became evident that any 

 attempt at a classification of the genera into families would 

 become extremely embarrassing, and of no permanent value. 

 This fact was altogether due to the progress of our knowledge 

 during the past twenty-five years and to the comparative com- 

 pleteness of the material under examination, which was sufficient 

 to show that the accepted subdivisions rec[uired important modifi- 

 cations before any satisfactory order could be brought out. For 

 these reasons it was deemed wiser to defer any such attempt and 

 reserve the discussions of the mutual relations of the genera for 

 separate chapters. The palaeozoic genera of the Brachiopoda 

 Inarticulata entire, and of the genera of the Articulata in part, from 

 Orthis toProductus inclusive, in that line of arrangement, have been 

 finally reviewed in accordance with the following list, as far as the 

 names in heavy-faced type extend, and this part of the list, therefore 

 represents the order of treatment and to some extent the present 

 understanding of the value of these genera. 



All non-binomial or prae-Linnean terms are omitted. 



Terms which are recognized, but with a subordinate value, are 

 inset, while undoubted synonyms are in italics.] 



I. Brachiopoda Inarticulata. 



1. Lingula, Bruguiere, 1789. 



2. Digrnomia, Hall, 1871. 



3. Glossina, Phillips, 1848, 



4. Pharetra, Bolten, 1798. 



5. Lingularius, Dumeril, 1806. 



6. Lingulops, Hall, 1871. 



7. Lingulasma, Ulrich, 1889. 



8. Lakhmina, (Ehlert, 1887. 



9. Davidsonella, Waagen, 1885. 



10. Trimerella, Billings, 1862. 



11. Gotlandia, Dall, 1870. 



12. Dinobolus, Hall, 1871. 



13. iConradia, Hall, MS., 1862.) 



14. Obolellina, Billings, (partim), 



1871. 



15. Monomerella, Billings, 1871. 



16. Rhinobolus, Hall, 1871. 



17. Lingulella, Salter, 1866. 



18. Lingulepis, Hall, 1863. 



19. Barroisella, gen. nov. 



20. Tomasina, gen. nov. 



21. Obolella, Billings, 1861. 



