CONTENTS 



Page 



*tt^ 



Introduction 5 



Stratigraphy of the Neichia Formation 5 



Description of species 7 



Genus Lingula Bruguiere 7 



1. Lingula sp 7 



Genus Orthis Dalman 7 



2. Orthis calligramma Dalman, var. simnsis Chang (var. nov.) 7 



3. Orthis calligramma Dalman, var. hv)pehensis Chang (var. nov.) 8 



4. Orthis carausii Salter, var. nanchanghsiensis Chang (var. nov,) 9 



5. Orthis ca?'ausii Saltev, MS lU 



6. Orthis neichiaensis Chang (sp. nov.) 11 



7. Orthis ellipsoides Chang (sp. nov.) 13 



8. Orthis calligramma Dalmau, var. intercalare Chang (var. nov.) 14 



9. Orthis cf unguis Sowerby 15 



10. Orthis cf. calligramma Dalman, var. subplicata Reed 15 



Genus Plectorthis Hall and Clarke 16 



11. Plectorthis sp. 1 16 



12. Plectorthis sp. 2 17 



Genus Dalmanella Hall and Clarke 17 



13. Dalmanella cf. elegantula Dalman 17 



Genus Rafinesquina Hall and Clarke 18 



14. Rafinesquina cf. muthensis Reed Ig 



Conclusion 19 



Bibliography 20 



Explanation of Plates 21 



