PLATES B47 



Explanation of Plates 



Plate 5. — Concretions 



Figure 1. — Concretion of cemented sand and fine gravel, Kenemich River, 

 Labrador. 



Figures 2 and 3. — Concretions attached to pebbles, Kenemich River, Labrador, 



Figures 4-8. — Concretions of irregular shape with thin outer shell of ferrugi- 

 nous material. Hamilton River, Labrador, 7 miles above mouth. 



Figure 9. — Subspherical concretion with outer shell of non-indurated ma- 

 terial, Kenemich River, Labrador. 



Figures 10 and 11. — Concretions with median constriction, south side Lake 

 Melville, Labrador. 



Figure 12. — Concretion with constrictions, south side Lake Melville. 



Plate 6. — Concretions 



Figures 1 and 2. — View of the two halves of a concretion showing the shell 

 of a Yoldia as the nucleus. 



Figure 3. — Concretion with a marine shell attached to the surface, Kenemich 

 River, Labrador. 



Figures 4 and 5. — Concretions with shells partially inclosed, Kenemich River, 

 Labrador. 



Figures 6, 7, and 9. — Concretions with thread-like ridges corresponding to 

 the lamination of the clays in which they were formed, Kene- 

 mich River, Labrador. 



Figure 8. — Concretion with iron-stained surface, Kenemich River, Labrador. 



Figures 10 and 11. — Views of the two halves of an egg-shaped concretion 

 from Macleod, Alberta. Figure 10 shows a piece of fossil wood 

 acting as the nucleus, while figure 11 indicates the external 

 appearance of the opposite half. 



Plate 7. — Concretions 



Figures 1 and 2. — Side and top views of terraced or discoid concretions. Fort 



Smith, Alberta. 

 Figures 3-6. — Compound discoid concretions, Endako, British Columbia. 



Plate 8. — Concretions 

 About two-fifths natural size. 



Figures 1 and 2. — Opposite sides of a concretion showing skull and other 

 parts of the skeleton of a marten, Ottawa River below Greens 

 Creek. 



Figures 3 and 4. — Concretion showing parts of three skeletons of Mallotus 

 villosus. 



