Clapp and Shimer. — Sutton Jurassic. 
PLATE 42. 
Fig. 16. Calamophyllia dawsoni n. sp. Photograph of a mass partlj' weath- 
ered from the Umestone. The weathering has taken place from 
the under side of the corallites. Xl|. 
Fig. 17. Isastrea vancouverensis n. sp. Photograph of a mass showing 
closely crowded corallites, their great length, and usually sub- 
circular cross-section. In the natural longitudinal sections the 
septa appear as ribs giving to the corallites a longitudinally 
striated appearance. XlJ- 
