Plate 12 



Page 



1. Hederella halyson (Fenton and Fenton, 1924) (see also pi. 2, fig. 6, and 



pi. 5, figs. 4, 5) 48 



A well-preserved colony showing the normal method of branching. 

 Devonian (Hackberry-Cerro Gordo shale), 3 miles southwest of 



Rockford, Iowa. 



2. Hederella fruticosa (Pocta, 1894). 



Portion of Pocta's enlarged view of the genotype of Thamnocoelum. 

 Silurian (Budnany limestone), Kosor, Bohemia. 



3. Hederella nodifera, new species 45 



The type specimen incrusting a brachiopod and showing the 



development of nodes at regular intervals on the branches. 

 Lower Devonian (Helderbergian-Birdsong shale), Perry ville, Tenn. 



4. Hederella nicholsoni, new species (see also pi. 4, figs. 8, 8') 44 



Portion of the type specimen attached to Spirifer mucronatus. 

 Middle Devonian (Traverse-Upper Bell shale), Rockport quarry, 

 Alpena County, Mich. 



5. Hederella michiganensis, new species (see also pi. 10, fig. 1) 54 



Portion of zoarium illustrating the method of branching. 

 Middle Devonian (Traverse-Gravel Point limestone), Lake shore, 

 Bay View, Mich. 



7. Hederella robusta, new species (see also pi. 10, fig. 2) 54 



6, A paratype believed to represent a simple growth form. 

 Hamilton (Moscow-Kashong shale), lyi miles southeast of East 



Bethany, N. Y. 



7, An example (paratype) incrusting a cup coral and showing very 



regular branching and budding of the large zooecia. 

 Hamilton (Ludlowville-Centerfield shale), 3 miles west of East 

 Bethany, N. Y. 



8. Hederella reimanni, new species 55 



Portion of the type specimen incrusting Athyris spiriferoides and 

 showing the large elongate tubes and the method of branching. 

 Hamilton (Ludlowville-Wanakah shale), Bay View, N. Y. 



87 



