Plate 4 



Page 



1, 2. HedereUa vagans, new species 38 



1, Portion of the loosely growing incrusting colony with the main 



axis a single tube branching at long, infrequent intervals. 



2, Small part of another example, showing more frequent branch- 



ing. 

 Hamilton (Widder shale), Thedford, Ontario. 

 3, 3'. HedereUa hibbardi, new species 55 



3, The type specimen incrusting Spirifer mucronatus arkonensis, a 



colony of short, wide, swollen zooecia with branches closely 



arranged. 

 3', Portion of another example, showing strong rugosities. 

 Hamilton (Arkona shale), Arkona, Ontario, and vicinity. 



4. HedereUa crassilinea, new species (see also pi. 13, figs. 4, 5) 41 



The holotype incrusting a cup coral and showing the linear main 

 axis branching at right angles at considerable intervals and 

 with short, thick zooecia budding at an angle of 45°. 



Devonian (Snyder Creek shale), Fulton, Mo. 



5. HedereUa pavilionensis, new species 43 



Colony incrusting a Fistulipora, resembling H. vagans but differing 



in its wider, longer zooecia. 

 Hamilton (Tichenor shale). Pavilion, N. Y. 



6. HedereUa germana, new species 39 



The type incrusting HeliophyUum, the zoarium differing from 

 H. vagans in the wider branches and the larger angle of 

 bifurcation. 



Hamilton (Widder shale), Thedford, Ontario. 



7. HedereUa edwardsi, new species 48 



Portion of a very complete colony incrusting a Spirifer with the 

 characteristic short, wide, frequently budding zooecia and 

 the branches dividing at short intervals. 



Middle Devonian (Milwaukee limestone-Lindwurm member), Mil- 

 waukee, Wis. 

 8, 8'. HedereUa nicholsoni, new species (.see also pi. 12, fig. 4) 44 



Two portions of the holotype incrusting Athyris spiriferoides and 

 illustrating differences in the method of division of the 

 branches and the rise of the zooecia at angles of about 45°. 



Hamilton (Ludlowville-Wanakah shale), 18-Mile Creek, N. Y. 



79 



