TYPE SPECIMENS OF PALEOZOIC FOSSILS 643, 



Orthoceras tetricum Hall 



4028 l fiA TYPE Orthoceras t e tri cum Hall. Descriptions of 



new species of fossils from the Upper Helderberg, Hamil- 

 ton and Chemung groups. 1861. p. 45. 



Hall. Paleontology of New York. 1879. v. 5, pt 2, 

 pi. 7 8B, fig. 4. 



Schoharie grit Clarksville, Albany co. N. Y, 



C. Van Deloo, coll. 1862 



4029 UfrL*- TYPE Hall. Paleontology of New York. 1879. v - 5> 



pt 2, pi. 80, fig. 2. 



Schoharie grit Clarksville N. Y. 



C. Van Deloo, coll. 1862 



4030 --^- TYPE Hall. Paleontology of New York. 1879 v - S> 



pt 2, pi. 80, fig. 5, 6. 



Schoharie grit Clarksville N. Y. 



C. Van Deloo, coll. 1862 



4031 2-^. TYPE Hall. Paleontology of New York. 1879. v. 5,pt2 r 



pi. 80, fig. 8. 



Schoharie grit Schoharie N. Y. 



J. Gebhard purchase 



4032 -^--f 1 - TYPE Hall. Paleontology of New York. 1879. v. 5, pt 2,. 



pi. 80, fig. 9. 



Schoharie grit Schoharie N. Y. 



J. Gebhard purchase 



Orthoceras tetricum see Orthoceras pravum 

 Orthoceras thestor see Orthoceras (Cycloceras)- 



thestor 



Orthoceras (Cycloceras) thestor Hall 



433 --y- A TYPE Orthoceras thestor Hall. Paleontology of 

 New York. 1879. v. 5, pt 2, p. 302, pi. 82, fig. 18. 



Marcellus shale Schoharie N. Y. 



J. Gebhard purchase 



Orthoceras thoas see Orthoceras (Dawson- 

 oceras) thoas 



Orthoceras (Dawsonoceras) thoas Hall 



4034 12.415. HYPOTYPE Orthoceras thoas Hall. Descriptions 

 of new species of fossils from the Upper Helderberg, 

 Hamilton and Chemung groups. 1861. p. 47. 



Hall. Illustrations of Devonian fossils. 1876. Cephal- 

 opoda, pi. 41, fig. i. 



