NEW OSTRACODERM— 0RVIG 23 



StensiO, E. a. 



1927. The Downtonian and Devonian vertebrates of Spitsbergen. 1 : Family 

 Cephalaspidae. Skrift. Svalb. Nordish., No. 12, 402 pp., 103 figs., 

 112 pis. 

 1948. On the Placodermi of the upper Devonian of East Greenland. 2: 

 Antiarchi. Subfamily Bothriolepinae. . . . Palaeozoologica Groen- 

 landica, vol. 2, 622 pp., 308 figs., 75 pis. 

 Stetson, H. C. 



1931. Studies on the morphology of the Heterostraci. Journ. Geol., vol. 39, 

 No. 2, pp. 141-154, 7 figs. 

 Sweet, W. C. 



1954. Harding and Fremont formations, Colorado. Bull. Amer. Assoc. 



Petr. Geol., vol. 38, pp. 284-305, 4 figs. 



1955. Conodonts from the Harding formation (middle Ordovician) of 



Colorado. Journ. Paleont., vol. 29, No. 2, pp. 226-262, 17 figs., 

 3 pis. 

 Tieje, a. J. 



1924. New earliest known vertebrates. (Abstract.) Bull. Geol. See. 

 Amer., vol. 35, No. 1, p. 1620. 

 Twenhofel, W. H., et al. 



1954. Correlation of the Ordovician formations of North America, by the 

 Ordovician Subcommittee of the Committee on Stratigraphy of 

 the National Research Council. Bull. Geol. Soc. Amer., vol. 65, 

 No. 3, pp. 247-298, 2 figs., 1 pi. 

 Ulrich, E. O. 



1938. Age of the Harding Sandstone fish remains. (Abstract.) Proc. 

 Geol. Soc. Amer. (1937), pp 289-290. 

 Vaillant, L:6on 



1902. Sur la presence du tissu osseux chez certains poissons des terrains 

 palaeozoiques de Canyon City (Colorado). Comptes Rendus 

 Acad. Sci. Paris, vol. 134, No. 22, pp. 1321-1322. 

 Walcott, C. D. 



1892. Notes on the discovery of a vertebrate fauna in Silurian (Ordovician) 

 strata. Bull. Geol. Soc. Amer., vol. 3, pp. 153-172, pis. 3-5. 

 White, E. I. 



1935. The Ostracoderm Pteraspis Kner and the relationships of the agna- 

 thous vertebrates. Phil. Trans. Roy. Soc. London, ser. b, vol. 

 225, No. 527, pp. 381-457, 97 figs., pis. 25-27. 

 Wills, L. J. 



1935. Rare and new ostracoderm fishes from the Downtonian of Shropshire. 

 Trans. Roy. Soc. Edinburgh, vol. 58, pt. 2, No. 18, pp. 427-447, 4 

 figs., 7 pis. 

 Woodward, A. S. 



1921. Visit to the gallery of fossil fishes, British Museum (Natural History). 

 Proc. Geol. Assoc, London, vol. 32, pt. 3, pp. 179-181, 2 figs. 



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