36 PKOCEEDINGS OF THE NATIONAL MUSEUM VOL.87 



Of the hundred or more specimens studied, this species maintains 

 its specific characters rather well, differences in its appearance being 

 due to the uneven surface it may incrust, or to old-age conditions in 

 which a regular mat is formed as in other species of the genus. 



Occurrence. — Middle Devonian: Arkona and Thedford and vicinity, 

 Ontario (Widder shale); 18-Mile Creek and Athol Springs (Wanakah), 

 Pavilion and IK miles south of East Bethany (Tichenor limestone), 

 IK miles southeast of East Bethany (Kashong shale), and 3 miles 

 west of East Bethany (Centerfield shale), all in New York; 2]i miles 

 southwest of Sylvania, Ohio (Silica shale); Milwaukee, Wis. (Mil- 

 waukee limestone); Rockport quarry (Upper Bell shale), Rockport 

 quarry and abandoned shale pit, Alpena Portland Cement Co. quarry 

 (Upper Ferron Point formation), 7-Mile Dam and K mile southeast of 

 4-Mile Dam, Alpena County (Norway Point formation), IK miles 

 northeast of Bay View and 1.6 miles north of Norwood, Charlevoix 

 County (Petoskey formation), ){ mile northwest Bolton, Alpena County 

 (Alpena limestone), all in Traverse group of Michigan. 



P/mof?/pes.— U.S.N.M. Nos. 13754, 57526, 71769, 87914, 87915. 



HEDERELLA BROWNAE, new species 



Plate 1, Figure 13 



This new species, based upon a well-preserved specimen incrusting a 

 Spirifer and collected by Dr. Ida Brown, of the University of Sydney, 

 is interesting as the first record of the suborder in Australia, and in its 

 close resemblance to the American species H. filiformis Billings. The 

 Australian species differs, however, in the greater length of the zooecia 

 (1.6 mm.) and the shorter interval (3 mm.), and the smaller angle 

 of branching (60°). The abundant American species H. thedfordensis 

 is quite similar in zoarial growth, but it has distinctly larger zooecial 

 measurements. 



Occurrence. — Middle Devonian: Taemas, south side of Murrum- 

 bidgee River, New South Wales. 



Holotype.—V.S.N.M. No. 97240. 



HEDERELLA ALTERNATA (Hall and Whitfield, 1873) 



Plate 5, Figures 1-3 



Stomatopora? alternata Hall and Whitfield, 23d Ann. Rep. New York State 



Mus., p. 235, pi. 10, figs. 7, 8, 1873. 

 Hederella alternata Fenton and Fenton, Strat. and Fauna Hackberry Stage, 



Upper Devonian, p. 72, pi. 17, figs. 5, 6, 1924. 



A species of moderate size for the genus, in which the alternate 

 arrangement of the zooecia in their development along the branches is 

 exceptionally well marked. Specimens growing upon rather smooth 

 brachiopod shells where the normal arrangement of the tubes has 



