TAB. XIII. 



Fig. 



1 a d. Cardium Groenlandicum, page \ 60. 



2 a, b. venustum, jo. 160. 



3 a, b. nodosulum, j. 154. 



c. portion of surface magnified. 



4 a, b. nodosum,jo. 153. 



c. portion of surface magnified. 

 50, b. strigilliferum, j. 154. 



d. portion of surface magnified. 



c. young specimen, showing the introduc- 



tion of an intermediate ray. 



6 a c. angustatum, p. 157. 

 70, b. Parkinsoni,jo. 158. 



The lines indicate the size of the specimens. 



