38 Annals of the Carnegie Museum. 



between the normally striate and the irregularly spinose types were 

 made out. The type is in the Carnegie Museum. 



Locality. — Specimens of Spirifer whitneyi and its varieties were 

 obtained from the gray limestone, number 4, and the green shale num- 

 ber 5, at all of the localities studied in detail by the writer, where the 

 Three Forks Formation is exposed in the region about Three Forks and 



to the north. 



Genus Amboccelia Hall. 



8. Amboccelia gregaria Hall. 



Amboccelia gregaria Hall, 13th Ann. Rept. N. Y. State Cab. Nat. Nist., p. 81. 

 Amboccelia gregaria Raymond, Ann. Carnegie Mus., Vol. V, 1909, p. 143. 



Specimens referred to this species are very common in certain of 

 the limestone bands in the green shale, number 5, particularly at 

 Three Forks and Logan. The brachial valves show the well-marked 

 sinus, which characterizes this species. 



Locality. — Green shale, member number 5, at Three Forks, Logan, 

 and localities to the north. 



Family RHYNCHONELLID^ Gray. 

 Genus Leiorhynchus Hall. 

 9. Leiorhynchus dunbarense sp. nov. (Plate VHI, fig. 8.) 

 C/. Leiorhynchus astabulense Prosser, Ohio Geol. Surv., 4th sen, Bull. 15, 1913. 



Shell very gibbous and wide in comparison with its height. The 

 ventral valve is slightly convex and the beak rather prominent. The 

 mesial sinus becomes very deep toward the margin and contains two 

 rather low, rounded plications. The sinus is bordered by two large 

 rounded plications, with usually two less elevated, rounded plications 

 on either side, the outermost usually faintly defined. The dorsal valve 

 is very convex and strongly incurved at the umbo, and rises some- 

 what above the ventral valve. The surface is marked by a high fold 

 with three rather angular plications. The sides have one strongly 

 marked plication next to the fold, and usually two less distinct, low, 

 rounded plications nearer the lateral margins. The surface of the 

 well-preserved specimens is covered with strong, concentric, imbricated 

 growth-lines. The dimensions of the type specimen are: width 27 mm., 

 height 16 mm. Another specimen has a width of 22 mm., and a 

 height of 14 mm. The type is in the Carnegie Museum. 



This species resembles Leiorhynchus astabulense Prosser in many 



