THE HEDERELLOIDEA — BASSLER 33 



low angle (30° or less) that they frequently remain in contact with it. 

 Closer measurements show that the diameter of the tubes is 0.3 mm., 

 with 5 to 6 tubes in 5 mm. Length of zooecial tubes about 0.75 mm.; 

 branching somewhat irregular but often at right angles and at inter- 

 vals of more than 5 mm. 



Occurrence. — Middle Devonian: Erie County (cotype) (Wanakah 

 shale), 3 miles west of East Bethany (cotype) and Livingstone 

 County (Centerfield shale), near Pavilion, lYz miles south of East 

 Bethany, and Daricn (Tichenor limestone), and Kashong Creek 

 (Ludlowville shale), all in New York; Thedford (cotype) and Arkona, 

 Ontario (Widder shale); Bell quarry, 2.1 miles east of Bay Shore, 

 Emmet County (Traverse-Gravel Point limestone) and IK miles 

 northeast of Bay View (Traverse-Petoskey formation), Mich.; San- 

 dusky, Ohio (Onondaga-Columbus limestone). 



Cotypcs.—U.^.'NM. Nos. 54078, 87955, 87957, 87961, 87884. 



HEDERELLA PARVIRUGOSA, new species 



Plate 6, Figures 12-14 



This new species shows considerable resemblance to H. concinna, 

 but comparison of the illustrations magnified on the same scale indi- 

 cates that it is larger in all its dimensions. The branches subdivide 

 at intervals of about 7 mm. when the growth is normal, in which case 

 4 zooecia occur in 5 mm. The zooecia are short, 1 mm. long and 0.35 

 mm. wide, expand rapidly and arise regularly at angles of about 45°, 

 often remaining free the greater part of the length. 



H. regularis is a related form but has smaller zooecial measurements, 

 with branching more frequent and more regular. H. arachnoidea is 

 similar but has less rapidly expanding zooecia. 



Occurrence. — Middle Devonian: Elma (cotype) (Wanakah shale), 

 Skaneateles Lake (Ludlowville shale), Moscow (cotype) (Moscow 

 shale). Pavilion (Tichenor limestone), and 1}^ miles southeast of East 

 Bethany (Kashong shale), all in New York; Thedford (cotype), 

 Marshs MUl, 2K miles east of Arkona, Ontario (Widder shale); 2% 

 miles southwest of Sylvania, Ohio (Silica shale); S% miles west of 

 Charlestown, Ind. (SUver Creek dolomite) ; and abandoned shale pit, 

 Alpena Portland Cement Co., Alpena County, Mich. (Traverse- 

 Upper Ferron Point formation). 



Cotypes.—V. S.l^.M. Nos. 10858, 54120, 78158, 87917-87921. 



HEDERELLA REGULARIS, new species 



Plate 8, Figures 1, 2 



Although apparently closely related to H. concinna in its micro- 

 scopic measurements, this species may be separated by the great 

 regularity not only in the branching of the zoarium but also in the size 



