230 CATALOGUE OF THE CRETACEOUS AND [bull. 152. 
Thyrsopteris dentata Font. Potomac Fl., p. 121, pi. xxiv, f. 4, 6, 7, 
9: xxv, f. 1,2, 1889. 
Potomac formation: Fredericksburg, Dutch Clap Canal, and near 
Potomac Run, Virginia. 
Thyrsopteris distans Font. Potomac FL, p. 134, pi. xlvii, f. 3; liv, 
f. 8, 1889. 
Potomac formation : Near Brooke, Virginia. 
Thyrsopteris divaricata Font. Potomac Fl., p. 125, pi. xxxvii, f. 
5-8; clxx, f. 1, 1889. 
Potomac formation : Fredericksburg and Dutch (lap Canal, Vir- 
ginia. 
Thyrsopteris elliptica Font. Potomac FL, p. 133, pi. xxiv, f. 3; xlvi, 
f. 1; 1, f. G, 9; li, f. 4, 6, 7; liv, f. 6; lv, f. 4; "lvi, f. 6, 7; lvii, f. G; Iviii, 
f. 2, 1889. 
Potomac formation: Fredericksburg and Dutch Gap Canal, Vir- 
ginia. 
Thyrsopteris heteroloba Font. Potomac FL, p. 139, pi. liii, f. 4, 
1889. 
Potomac formation : Fredericksburg, Virginia. 
Thyrsopteris heteromorpha Font. Potomac FL, p. 136, pi. lii, f. 1, 
1889. 
Potomac formation : Fredericksburg, Virginia. 
Thyrsopteris heterophylla Font. Potomac FL, p. 142, pi. Iviii, f. 3, 
1889. 
Potomac formation: Fredericksburg, Virginia. 
Thyrsopteris inaequipinnata Font. Potomac FL, p. 142, pi. lvii, f. 3, 
8, 1889. 
Potomac formation : Near Dutch Gap Canal, Virginia. 
Thyrsopteris insignis Font. Potomac. FL, p. 127, pi. xxxix, f. 4; xl, 
f. 1; xli, f. 6; xlii, f. 1, 2, 4; xliii, f. 1, 3, 1889. 
Potomac formation: Fredericksburg and near Potomac Run, Vir- 
ginia. 
Kootanie : Great Falls, Montana. 
Thyrsopteris insignis angustipennis Font. Potomac FL, p. 128, pi. 
xlii, f. 3; xliii, f. 2, 1889. 
Potomac formation : Fredericksburg, Virginia. 
Thyrsopteris Meekiana Font. Potomac FL, p. 125, pi. xxxviii, f. 
2-4,8; 1, f. 7,8: li, f. 3, 1889. 
Potomac formation : Fredericksburg and near Dutch Gap Canal, 
Virginia; Baltimore, Maryland. 
Thyrsopteris Meekiana angustiloba Font. Potomac FL, p. 126, pi. 
xxxviii, f. 5-7, 9 ; xliii, f. 8; xliv, f. 3; xlvii, f. 4; xlviii, f. 1; liv, f. 2, 
11; lv.f. 1; lvi, f. 1,3, 1889. 
Potomac formation: Baltimore, Maryland; near Dutch Gap Canal, 
near Brooke, and Fredericksburg, Virginia. 
Thyrsopteris microloba Font. Potomac FL, p. 140, pi. lvii, f. 4, 1889. 
Potomac formation: Near Dutch Gap Canal, Virginia. 
