40 PROCEEDINGS OF THE NATIONAL MUSEUM vol.87 



Occurrence. — Onondaga (Upper Jeffersonville limestone-5'pinyer 

 acuminatus bed): Falls of the Ohio. 

 Cotypes—U.S.'NM. No. 87954. 



HEDERELLA ANGULATA (Davis, 1885) 



Plate 7, Figures 5, 6 

 Nicholsonia angulata Davis, Kentucky Foss. Corals, pi. 80, fig. 15, 1885. 



A species much like H. vagans but differing in that the primary- 

 axial tubes, 0.3 mm. in width, give rise at short intervals (1.5 mm. to 

 3 mm.) to long secondary branches at more or less of a right angle, 

 from which in turn emerge very short zooecia (0.5 mm.) at intervals 

 of 2 to 3 mm. at a 45° angle with 1 to 2 in 5 mm. Surface very 

 delicately annulated. Comparisons with H. rectifurcata are given 

 under description of the latter. 



Occurrence. — Onondaga (Upper Jeffersonville limestone-Spirifer 

 acuminatus zone): Falls of the Ohio. 



Plesiotype.—U. S.N.M. No. 54092. 



HEDERELLA TENERA, new species 



Plate 7, Figures 7-9 



Associated with H. angulata is a more delicate species also closely 

 related to H. vagans but distinguished from both by its narrow 

 branches (0.25 mm. in width), which subdivide at an angle less than 

 45° at intervals of 1.5 to 2 mm., with longer zooecia (1.3 mm. and 3 

 in 5 mm.) emerging at an equally small angle at long distances. In 

 this, as in the related species, the surface ornament is exceedingly 

 delicate and the transversely oval zooecial apertures bend slightly 

 upward. 



Occurrence. — Onondaga (Upper Jeffersonville ]imestoTie-Spirifer 

 acuminatus bed): Falls of the Ohio. 



Cotypes—U. S.'N.M. No. 87913. 



HEDERELLA ULRICHI, new species 



Plate 13, Figure 8 



This species is based upon a mold in sandstone, gutta-percha 

 squeezes of which indicate a form related to H. crassilinea from the 

 Snyder Creek shale of Missouri but differing in that the zooecia are 

 larger (2 mm. long and 0.7 mm. wide, with 2% in 5 mm.) and bud 

 alternately from the main axis at smaller angles (less than 45°) so 

 that they form narrow branches, which in themselves bifurcate at 

 distances of about 10 mm. Better specimens will show other char- 

 acters for this robust species. 



The specific name is in honor of Dr. E. O. Ulrich, who collected the 

 type specimen. 



