685 Plat. 



horns." Multitudes of them occur in spots at various places 

 along the outcrop ; and the rock is often completely honey- 

 combed with their casts. These abound also in the upper part 

 cf the formation where it rises with a moderate dip at the Oar 

 works at Huntingdon on the north side of the basin (T3, p. 

 257, 270, 274). In Bedford county they abound in the Oris- 

 kany sandstone outcrop on the south side of Bedford Springs, 

 but not in a good state of preservation; also along Wills' creek 

 to the Maryland line, as at Hyndman station, where they crowd 

 the bottom calcareous sandstone bed (142' below the top of 

 the formation) No. 40 of the section, which makes the top- 

 most stratum of the cherty limestone upper member of the 

 Lower Helderherg formation (T2, p. 86, 104, 148). They oc- 

 cur in the corresponding limey sandstone at the end of Royers' 

 Ridge, Orbisonia, Aughwick Valley, Huntingdon (Jo. See spec. 

 703-8, of Ashburner & Hall's collections.— F//. 



Platyceras, of undetermined species, is reported by I. C. 

 White in G 7, page 289, as one of the Hamilton forms vi\ bed No. 

 75 of his Catawissa-Bloomsburg section in Columbia Co., Pa., 

 just underlying the Oenesee shale, and therefore corresponding 

 to the Tully limestone of New York ; but without a single one of 

 the Tully fossils. It occurs also in the same rock on Little 

 Fishing creek north of Montour ridge (G7, 75).— VIII f. Pos- 

 sibly this is the horizon of a Platyceras (Specimen 801-16) in 

 Chance's collections on Marshall's creek, Monroe Co., 1^ miles 

 north of Craig's meadow. (00, p. 237.) 



Platyceras, numerous in Randall's section, divisions F, G 

 and H (Report IIII, p. 305). VIII-IX. 



Platyceras, abundant below the Third Mountain Sand 

 at two places in Venango Co., Pa., one 3 m. N. 50° W., the 

 other 2| m. N. W. of Pleasantville ; in strata lying, the one 300', 

 the other 250' beneath the Second Mountain sand. Report I, p. 

 79. X 



Platyceras, in Third Mountain sand (IIII p. 273). X. 



Platyceras, a fine specimen collected by Hatch, near the 

 base of a fine exposure of the Second Mountain sand {Oorry 

 sandstone of I. C. White) in Warren Co., Pa., near the Craw- 

 ford Co. line (Q4, p. 93.) X. 



Platyceras appears in the middle 200' of Randall's section 

 at Warren (/*), underneath the First Mountain sand or fish 



