TYPE SPECIMENS OF PALEOZOIC FOSSILS 643 



Orthoceras tetricum Hall 



4028 1 ^f i - type Orthoceras tetricum 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. 78B, fig. 4. 



Schoharie grit Clarksville, Albany co. N. Y. 



C. Van Deloo, coll. 1862 



4029 — ip- 3 - 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 —-J— type Hall. Paleontology of New York. 1879 v. 5, 



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



Schoharie grit Clarksville N. Y. 



C. Van Deloo, coll. 1862 



4031 — f-- 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 



4033 * 2 f l ± 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 J-^Aii 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. 1S76. Cephal- 

 opoda, pi. 41, fig. 1. 



