52 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 8t 



Zoarium incrusting cup corals and other organisms over consider- 

 able areas and consisting of large, swollen zooecia 2.2 nun. long and 

 1 mm. wide at the aperture, emerging alternately from a long central 

 tube, which may be as much as 15 mm. in length before bending 

 outward as a typical zooecium and giving rise to another similar tube 

 from which the zooecia bud. Branching rather infrequent, with 

 sometimes an interval of 20 mm. Zooecia short for their size, rapidly 

 expanding, with 2 to 2.5 in 5 mm. measuring on one side of a branch, 

 and usually adherent throughout the length (angle of less than 20°). 

 Surface with delicate annulations throughout and coarser wrinkles 

 taking the place of every third or fourth annulation. Apertures fairly 

 round and bent slightly upward. 



The robust zoarium with short, wide zooecia in contact and regular 

 arrangement and the infrequent branchmg characterize this fine 

 species. 



Occurrence. — Middle Devonian: Bay View, etc., Erie County, York 

 (plesiotype) (Wanakah shale). Pavilion (Tichenor limestone), 3 miles 

 west of East Bethany and Murder Creek, Darien (Centerfield shale), 

 and 18-Mile Creek (Moscow shale), all in New York; Arkona (Arkona 

 shale) and Thedford (Widder shale), Ontario; 2)^ miles southwest of 

 Sylvania, Ohio (Silica shale). 



P/mo#?/pe.— U.S.N.M. Nos. 54107, 87912, 87962-87966. 



HEDERELLA MAGNA PRAECEDENS. nev* variety 



Plate 3, Figure 11 



Hederella magna Clarke, Mem. New York State Mus., vol. 3, No. 3, p. 61, pi. 9, 

 fig. 10, 1900. 



Zooecia shorter (2.0 mm. in length and 1.0 mm. wide) and blunter 

 than in typical H. magna, with about 3 instead of 2.5 in 5 mm. 



The single specimen upon which this variety is founded shows that 

 it differs from the typical Hamilton form in its longer, blunter, more 

 parallel-edged tubes arising at such a narrow angle as to remain in 

 close contact. Branching appears to occur at shorter intervals and 

 other specimens may show further differences. 



Occurrence. — Oriskany sandstone: Becraft Mountain near Hudson, 

 N. Y. 



Plastoholotype.—U.S.'!<i.M. No. 94163. 



HEDERELLA MAGNIVENTRA, new species 



Plate 10, Figures 5, 6 



This vigorous species may be easUy recognized by its broad, stout, 

 linear branches with a single row of tubes dividing at irregular and 

 sometimes long intervals, usually at a right angle, with the zooecia 



