22 G. HOLM AND A. H. WESTEEGAAUD 



Schmidt, F., 1904. Ausgang und Resultate der russischen Polarexpedition unter Baron E. v. Toll. 



Centralblatt fiir Min., Geol. und Pal., Jahrg. 1904, pp. 225—232. Nachtrag. Ibid., 



pp. 437—440. Weiterer Nachtrag. Ibid., p. 527. 8". Stuttgart. 

 von Toll, Eduard, 1899. Beitrage zur Kenntniss des sibirischen Cambrium. I. M6m. de I'Acad. 



Imp. des Sc. de St.-P6tersbourg, VIII s6r., vol. VIII, No. 10. 4°. St.-Petersbourg. 

 von Toll, Eduard, 1909. Die russische Polarfahrt der "Sarja" 1900 — 1902. Herausgegeben von 



Baronin Emmy von Toll. 8". Berlin. 

 Tullberg, S. A., 1880. Om Agnostus-artema i de kambriska aflagringarna vid Andrarum. Sver. 



Geol. Unders., ser. C, No. 42. 4°. Stockholm. 

 Walcott, C. D., 1911. Cambrian geology and paleontology, vol. II, No. 4. Smithsonian Misc. Coll. 



vol. 57, No. 4. 8^ Washington. 

 Walcott, C. D., 1912. Cambrian Brachiopoda. Monographs of the U. S. Geol. Sm-vey, vol. II. 4". 



Washington. 

 Walcott, C. D., 1913. The Cambrian faunas of China. Res. in China, vol. III. Carnegie Instit. 



of Washington. 4". Washington. 

 Walcott, C. D., 1916. Cambrian geology and paleontology, vol. Ill, No. 5. Smithsonian Misc. Coll., 



vol. 64, No. 5. 8". Washington. 

 Wiman, Carl, 1906. Paleontologische Notizen 7 — 12. Bull. Geol. Instit. Upsala, vol. VII. 8°. Upsala. 



As the present writer does not read Russian, reports in that language are omitted from the 

 above list. In the above-mentioned work by Obrutschew is to be found a complete bibliography 

 of publications dealing with the geology of Siberia issued before 1926. 



EXPLANATION OF PLATES 



PLATE I 



Fig. 1. Agnostus pisiformis pater n. subsp. Pygidium; preserved in limestone. Cat. No. 2073/100. 

 Fig. 2. Agnostus glandiformis Angelin. Cephalon; preserved in limestone. Cat. No. 314/1110. 

 Fig. 3. Agnostus glmidiformis Angelin. Pygidium, somewhat flattened. Cat. No. 314/1107. 

 Fig. 4a-c. Agnostus glandiformis Angelin. Somewhat distorted pygidium, seen in different aspects; 



preserved in limestone. Cat. No. 314/1105. 

 Fig. 5. Agnostus glandiformis Angelin. Pygidium of young specimen, probably of this species. 



Cat. No. 2073/131. 

 Fig. 6 a-d. Agnostus nudus hyperboreus n. subsp. Rolled up, complete, somewhat distorted, young 



specimen, seen in different aspects. Cat. No. 314/1114. 

 Fig. 7, 8. Agnostus nudus hyperboreus n. subsp. Cephala. Cat. Nos. 314/1121 and 314/1107 resp. 



(The former slab is the counterpart of the latter). 

 Fig. 9. Agnostus nudus hyperboreus n. subsp. Pygidium. Cat. No. 314/1125. 

 Fig. 10. Agnostus bituberculatus Angelin. Cephalon; preserved in limestone. Cat. No. 2073/100. 

 Fig. 11, 12. Agnostus bituberculatus Angelin. Pygidia, with some hesitation referred to this species. 



Cat. No. 314/1114. 

 Fig. 13. Agnostus sp. No. \. Pygidium of young specimen. Cat. No. 314/1109. 

 Fig, 14—23. Agnostus latirhachis n. sp. Pygidia of young specimens. — Fig. 14, 17. Cat. 



No. 314/1108. — Fig. 15, 20, 22. Cat. No. 314/1107. — Fig. 16, 19, 23. Cat. No. 314/1114.— 



Fig. 18. Cat. No. 314/1111. — Fig. 21. Cat. No. 314/1118. 

 Fig. 24. Agnostus latirhachis n. sp. Pygidium of immature specimen with two thoracic segments 



still attached. This species? Cat. No. 314/1114. 

 Fig. 25. Agnostus latirhachis n. sp. Pygidium of immature specimen, with hesitation referred to 



this species. Cat. No. 314/1118. 



