176 PROCEEDINGS OF TRE NATIONAL MUSEUM. vol.xxii. 



EXPLANATION OF PLATES. 



[From drawings by Mr. E. O. Uleich.] 



Plate XII. 

 Porocrinus shawi, p. 155. 



Fig. 1 . Posterior view of the calyx ; enlarged. 



2. Anterior view; natural size. 



3. Ventral view; enlarged. 



Dalmanites (Pterygometoptis) goodridgii, p. 174. 



4. The pygidium supposed to be of this species. 



5. 6. Two views of the cephalon. 



Orthis (Dinorthis) meedsi arctica, p. 157. 

 7, 8. Dorsal and profile views. 



Seelya (?) (Plethospira ?) ulrichi, p. 166. 

 9, 10. Two views showing the nearly obsolete revolving bands. 



Troohus f, species nndetermiued, p. 168. 

 11-13. Three views of the only specimeu of this genus. 

 Holopea arctica, p. 168. 



14, 15. Two views of the best specimen. 



16. Surface ornamentation ; x5. 



Orthoceras scalariformis, p. 170. 



17. The ornamentation. 



18. Sectional view, with the position of the sipho. 



Orthoceras olorus baffinensis, p. 169. 



19. 21, 22. Views of three specimens. 



20. Surface ornamentation; xlO. 



Orthoceras porteri, p. 169. 



23. View of the exterior. 



24. Surface ornamentation ; x5. 



25. Sectional view, with the position of the sipho. 



Plate XIII. 



Ctenodonia carpenderi, p. 160. 



Figs. 1-3. Three views of the largest specimen. 



Ctenodonia snhnasuta Ulrich?, p. 160. 



4-6. Three views of the best specimen. 



Ctenodonia baffinensis. p. 161. 



7-9. Three views of the type specimen. 

 10. Surface ornamentation; xlO. 



Ctenodonia frobisherensis, p. 161. 



11-13. Three views of the best specimen. 

 14. Left valve of another specimen. 



Whiteavesia symmetricns, p. 162, 

 15-17, Three views of the type specimen. 



