306 BIBLIOGRAPHY OF NORTH AMERICAN GEOLOGY, 1906-1907. 
Point Pleasant formation, Ordovician, Ohio 
and Kentucky : Bassler, 156. 
Poison Canyon formation, Cretaceous r, 
Colorado : Darton, 648. 
Polk Bayou limestone, Ordovician, Arkan- 
sas : Purdue, 1970. 
Pomfret phyllite, Connecticut : Gregory, 
1034 ; Gregory and Robinson, 1038. 
Poor Mountain zone, Cambrian?, South 
Carolina: Sloan, 2218. 
Portage member, Devonian, Maryland : 
Clark and Mathews, 488. 
Port Clarence limestone, Silurian, Alaska : 
Brooks, 313. 
Porters Creek clay, Cretaceous, Mississippi : 
Crider, 598. 
Porters Creek clay, Tertiary, Mississippi : 
Crider, 595 ; Crider and Johnson, 599. 
Porters Creek (Flatwoods) clay, Eocene, 
Mississippi : Logan, 1608. 
Porters Creek formation, Tertiary, Illinois : 
Purdy and DeWolf, 1973. 
Porters Creek formation, Tertiary, Mis- 
souri : Shepard, 2194. 
Porters Creek formation, Tertiary, Ten- 
nessee, Kentucky, and Illinois : Glenn, 
971. 
Port Ewen limestone, Devonian, New York : 
Grabau, 991. 
Port Hudson formation, Quaternary, Mis- 
sissippi : Crider, 595 ; Crider and John- 
son, 599. 
Port Hudson formation, Quaternary. Lou- 
isiana and Arkansas : Veatch, 2436. 
Port Renfrew series, Vancouver Island : 
Hall, 1064. 
Potapaco member, Eocene, Maryland : Shat- 
tuck et al., 2193. 
Potem formation, Jurassic, California : Dil- 
leiC 721. 
Potomac formation. Cretaceous, Mississippi : 
Logan and Hand, 1609. 
Potomac formation, Cretaceous, South Caro- 
lina : Pugh, 1963. 
Potomac group, Cretaceous, Maryland and 
Delaware : Miller, 1749. 
Potomac group, Jurassic? and Cretaceous, 
Maryland : Shattuck et al, 2193. 
Potomac group. Jurassic-Cretaceous, Mary- 
land : Clark and Mathews, 488. 
Potosi volcanic series, Colorado : Cross 
et al., 607. 
Potsdam sandstone, Cambrian, Illinois : 
Weller, 2517, 2524. 
Potsdam sandstone, Cambrian, Wisconsin : 
Grant, 1017 ; Weidman, 2512. 
Potsdam series, Cambrian, Iowa : Beyer and 
Williams, 234. 
Potsdam, Ordovician, Mississippi Valley : 
Davis, 663. 
Pottsville conglomerate, Lower Carbonifer- 
ous, Pennsylvania : Barrell, 150. 
Pottsville formation, Carboniferous, Ohio : 
Carney, 427. 
Pottsville formation, Carboniferous, Penn- 
sylvania : Butts, 368 ; Clapp, 475, 477 ; 
Woolsey, 2634. 
Pottsville formation, Carboniferous, Penn- 
sylvania, Ohio, and West Virginia : Gris- 
wold and Munn, 1048. 
Pottsville formation, Pennsylvanian, Mary- 
land : Clark and Mathews, 488. 
Pottsville series, Carboniferous, West Vir- 
ginia : Grimsley, 1044. 
Poughquag quartzite, Connecticut : Gregory, 
1034. 
I'oughquag quartzite, Cambrian, Connecti- 
cut : Gregory and Robinson, 1038. 
ronghquag quartzite, Cambrian, New York : 
Berkey, 207. 
I'oughquag quartzite, Cambro-Ordovician, 
Connecticut: Hobbs, 1185. 
Powers Bluff quartzite, pre-Cambrian, Wis- 
consin : Weidman, 2512. 
Prairie du Chien formation, Ordovician, 
upper Mississippi Valley : Bain, 99. 
Prairie du Chien limestone, Ordovician, 
Iowa : Beyer and Williams, 234. 
Prairie du Chien formation, Ordovician, 
Wisconsin : Grant and Burchard, 1021. 
Prattsburg shales and flags, Devonian, 
New York : Luther, 1634. 
Pre-Kansan, Quaternary, Iowa : Calvin, 387. 
Preston formation, Cretaceous, Arkansas : 
A'eatch, 2436. 
Preston gabbro-diorite, Connecticut : Greg- 
ory and Robinson, 1038. 
Prichard (?) formation, prorCambrian, 
Montana : Emmons, 800. 
Trichard slate, Algonkian, Montana : Wal- 
cott, 2470. 
Prospect porphyritic gneiss, Connecticut! 
Gregory, 1034 ; Gregory and Robinson, 
1038. 
Prospect Mountain quartzite, Cambrian?, 
Nevada and California: Ball, 120. 
Prosperity limestone, Carboniferous, Penn- 
sylvania : Clapp, 475. 
Prosperity limestone. Carboniferous, Penn- 
sylvania, Ohio, and West Virginia : Gris- 
wold and Munn, 1048. 
Prout limestone, Devonian, Ohio : Stauffer, 
2277. 
Providence Cove beds, Vancouver Island : 
Hall, 1064. 
Puente shale, Miocene, California : Eld- 
ridge and Arnold, 779. 
Puerco, Tertiary, Wyoming : Veatch, 2439. 
Puerco marls, Eocene, New Mexico : Keyes, 
1388. 
Fuerco marl. Eocene, Colorado and New 
Mexico: Shaler, 2176. 
Puerco marls, Eocene, New Mexico : Keyes, 
1390. 
Puget group, Cretaceous, Washington : 
Arnold, 56. 
Puget group, Tertiary, British Columbia : 
Brooks, 313. 
Pulliam formation, Cretaceous, Texas : Ud- 
den, 2408. 
Purgatory conglomerate, Massachusetts 
Mansfield, 1674. 
Purisima formation, Tertiary, California 
Arnold, 57. 
