Plate 11 



Page 



1-8. Ilederella delicatula, new species 38 



1, A typical zoarium incrusting a Heliophyllum and illustrating 



the delicacy of the tubes and the method of branching. 

 Hamilton (Ludlowville-Wanakah shale), Erie County, N. Y. 



2, An example growing on a cup coral with crowded branches 



caused by several colonies crossing one another in the course 

 of growth. 



3, 4, Portion of a colony, and a part X 8, showing the structure 



in more detail and demonstrating that branches of the same 



colony will cross one another. 

 Hamilton (Ludlowville-Tichenor limestone), l^i miles south of 



East Bethany, N. Y. 

 5, A small example incrusting a crinoid column. 

 Hamilton (Widder shale), Thedford, Ontario, 

 f), Colony attached to a stony bryozoan (Lioclema) . 

 Middle Devonian (Milwaukee limestone-Lindwurm member), 



Milwaukee, Wis. 



7, An unusual example, doubtfully referred to this species, in 



which branching has occurred in such way that the tubes 

 appear in two rows. 

 Onondaga (Upper JefTersonville limestone). Falls of the Ohio. 



8, Two species of Hederella, the smaller one identified as H. deli- 



catula and the larger as H. bilineata. 

 Hamilton (Sellersburg limestone), Lebanon, Ky. 



9. Hederella concinnoides, new species 37 



The type specimen, similar to H. delicatula but with slightly 



wider tubes and zooecia emerging at a greater angle. 

 Middle Devonian (Silica shale), 2;-2 miles southwest of Sylvania, 

 Ohio. 

 10-12. Hederella adnata (Davis, 1885) 46 



10, Example incrusting a bryozoan (Polypora), with branching 

 somewhat less regular than usual. 



11, Tubes attached to the noncelluliferous side of a bryozoan, 

 showing normal method of branching. 



12, Portion of fig. 11, X 8, exhibiting structure in more detail. 

 Onondaga (Upper JefTersonville limestone). Falls of the Ohio. 



86 



