weeks.] PALEONTOLOGY, PETROLOGY, AND MINERALOGY, 1901. 139 
Paleontology— Continued . 
Genera and species described— Continued. 
Tretaspis diademata n. sp., Ruedemann, 660. 
reticulatus n. sp., Ruedemann, 660. 
Triacodon fallax Marsh, Wortman, 863. 
Triarthrus becki, Beecher, 51.. 
Trigeria? curriei n. sp., Rowley, 658. 
Trigonias osborni n. sp., Lucas, 501. 
Trigonoarca decisa (Conrad) var., Clark and 
Martin, 141. 
Triisodon heilprianus Cope, Matthew, 538. 
Trionyx Virginia Clark, Case, 120. 
Trinucleus, Beecher, 51. 
Tritonium showalteri (Conrad), Clark and 
Martin, 141. 
Trochoceras Hall, Grabau, 306. 
gebhardi Hall, Grabau, 306. 
Trochocyathus clarkeanus Vaughan, Vaugh- 
an, 765. 
Trochonema emacerata Hall and Whitf., 
Kindle, 442. 
rectilatera Hall and Whitfield, Kindle,442. 
umbilicatum Hall sp., Ruedemann, 660. 
Trophon sublevis Harris, Clark and Martin, 
141. 
Tropidoleptuscarinatus (Conrad), Kindle, 412. 
Truncatulina lobatula (Walker and Jacob), 
Bagg, 35. 
ungeriana (d'Orbigny), Bagg, 35. 
Tryblidium exsertum n. sp., Sardeson, 677. 
validum n. sp., Sardeson, 677. 
Tuba marylandica n. sp., Clark and Martin, 
141. 
Tudicla marylandica n. sp., Clark and Mar- 
tin, 141. 
sp., Clark and Martin, 141. 
Turbinolia acuticostata Vaughan, Vaughan, 
765. 
Turbo shumardi De Verneuil, Kindle, 442. 
Turbonilia potomacensis n. sp., Clark and 
Martin, 141. 
Turrilepas(?) filosa n. sp., Ruedemann, 659. 
Turritella humerosa Conrad, Clark and Mar- 
tin, 141. 
mortoni Conrad, Clark and Martin, 141. 
potomacensis n. sp., Clarkand Martin, 141. 
Uintacyon Leidy, Wortman, 861. 
edax Leidy, Wortman, 861. 
Unio Retzius, Letson, 493. 
gibbosus Barnes, Letson, 493. 
nanaimoensis n. sp., Whiteaves, 819. 
Urotheca n. gen., Matthew, 529. 
pervetus n. sp., Matthew, 529. 
Vaginulina legumen (Linne), Bagg, 35. 
Valvata Muller, Letson, 493. 
sincera Say, Letson, 493. 
tricarinata Say, Letson, 493. 
Venericardia marylandica n. sp., Clark and 
Martin, 141. 
planicostata var. regia Conrad, Clark and 
Martin, 141. 
potapacoensisn. sp., Clark and Martin, 141. 
Vermetus sp., Clark and Martin, 141. 
Vicarya callosa var., Becker, 50. 
semperi n. var., Becker, 50. 
Vitulina pustulosa Hall, Kindle, 442. 
Viverravus Marsh, Matthew, 538. 
Paleontology— Continued. 
Genera and species described— Continued 
Viverravus Marsh, Wortman, 862. 
gracilis Marsh, Wortman, 862. 
minutus n. sp., Wortman, 862. 
Volutilithes petrosus (Conrad), Clark and 
Martin, 141. 
sp., Clark and Martin, 141. 
Vulpavus Marsh, Wortman, 891. 
hargeri n. sp., Wortman, 861. 
palnstris Marsh, Wortman, 861. 
Westonia n. subgen., Walcott, 771. 
Whitfieldella Hall and Clarke, Grabau, 306. 
cylindrica Hall, Grabau, 306. 
intermedia Hall, Grabau, 306. 
laevis (Whitfield), Grabau, 306. 
nitida Hall, Grabau, 306. 
var. oblata Hall, Grabau, 306. 
oblata Hall, Grabau, 306. 
sulcata (Vanuxem), Grabau, 306. 
Whitfleldella nitida Hall 1843, Beecher, 51. 
Whittleseya Newbury 1853, White, 813. 
brevifolia n. sp., White, 813. 
dawsoniana n. sp., White, 813. 
desiderata n. sp., White, 813. 
Worthenia mississippiensis (W. & W.), Wel- 
ler, 804. 
Xiphias (? radiata Clark), Case, 251. 
Zaphrentis Rafinesque, Grabau, 306. 
albus n. sp., Greene, 319. 
curtus n. sp., Greene, 319. 
inflexus n. sp., Greene, 319. 
insolens n. sp., Greene, 319. 
lamasteri n. sp., Greene, 319. 
obscurus n. sp., Greene, 320. 
pusillus n. sp., Greene, 319. 
turbinati (Hall), Grabau, 306. 
Ziphacodon rugatus Marsh, Wortman, 863. 
Zygospira, Beecher, 51. 
aquila n. sp., Sardeson, 677. 
recurvirostris Hall, Ruedemann, 660. 
Panama. 
Geology of the Isthmus of Panama, Hershey, 
365. 
Pennsylvania. 
Age of the coals at Tipton, White, 810. 
Alleged Parker channel, Williams, 825. 
Anthracite coal near Perkiomen Creek, Car- 
ter, 108. 
Buried valley of Wyoming, Griffith, 328. 
Caves of Huntingdon County, Morganroth, 
557. 
Graphite and garnet, Hopkins, 389. 
Limestones in the vicinity of Philadelphia, 
Carter, 115. 
New species of Olenellus, Wanner, 776. 
Occurrence of serpentine and talc, Peck, 590. 
Oil and gas in the vicinity of Philadelphia, 
Carter, 109. 
On spangolite, Penfield, 595. 
Troost's survey of Philadelphia, Hamilton, 336. 
Water supply for Philadelphia, Carter, 106. 
Petrology. 
California. 
Berkeley Hills. Lawson and Palache, 484a. 
California feldspar-corundum rocks from Plu- 
mas County, Lawson, 482. 
