Plat. 



684 



Platycerrs ventricosum, Oonrad, Annual Report of New 



York 

 Survey, 



1840. 

 Geology 

 of Can- 

 ada, 

 1863, 

 page 

 ^58, fig. 

 461. 

 Hall, 

 Pal. N. 

 Y. Vol. 

 3, lh59, 

 ;46] p. 310, figs. 1, 2. Lower Helderherg 

 formation, VI. — In Pennsylvania, 

 found along the Pike and Monroe 

 countyoutcropof the Oriskany^ especi- 

 ally on Broadhe ad's Creek (G6, p. 123, 

 124) ; also, in Montour county. Cooper 

 Geof^^^^^^^^^Qjy^^ township, at Grove Bro.'s tunnel, at 

 Hartzell's quarry, and along Chilisquaque Creek (G7, p. 86^ 

 297, 305, 310) ; also in Huntingdon Co. at Mapleton (T3, 119), 

 and at Three Springs and Orbisonia (T, 35, and 0. E. Hall's 

 MS. report 1875). See Claypole's catalogue (in 000) Spec. 

 95-3 (four), 200-4 (two), from Grove Bro.'s quarry, Columbia 

 Co , and 200-4 (two) from Mapleton, Huntingdon Co. VIL 



Platyceras- ? {Orthonijchia ?) Hall, Geology of the 



y/lj ^^ Fourth District ot New York, 1843, 



^- ^^^^^^^^^ P^^^ ^'^^' ^^' ^^' ^ ^^^^ ^' ^-^^^ 

 o/i A^^^^^^^^^^m Helderherg formation. VIII a. 



Platyceras, of several ppecies, abound in all the Oriskany 

 glass-sand quarries at Mapleton, Huntingdon Co., Pa., and 

 along Sand Ridge, east and west from the Juniata river, where 

 the formation stand* nearly vertical on the southeast side of 

 the great basin. They are known by the quarrymen as "cows 



