Fig. 
Fig. 
3a. 
PLATE V. 
HELIOPHYLLUM CANADENSE, Billings. 
HELIOPHYLLUM CayUGAENSE, Billings. 
size. (p. 26.) 
HELIOPHYLLUM COLLIGATUM, Billings. 
size. (p. 28.) 
Nat. size. 
The calice viewed from above. 
Upper surface of a fragment. 
(p. 25.) 
Nat. 
Nat. 
Side-view of the same, showing the periodic expansions of the corallites. Nat. 
size. 
HELIOPHYLLUM COLBORNENSE, Nich, Nat. size. 
DIPHYPHYLLUM GRACILE, McCoy. Nat. size. 
DIPHYPHYLLUM STRAMINEUM, Billings. 
(p. 25.) 
(p. 33.) 
Nat size. (p. 33.) 
