Questions as to the Origin and Extinction of Species. 415 
Table of Erian and Carboniferous Specific Types. 
; age a5 
= Erian Types. Represented ee. Erian Types. Represented gale 
a in Carboniferous— alee in Carboniferous— SS /28 
| BSB PS ibs 
1. Syringoxylon mirabile, - --_- 21. Cordaites Robbii,....._._- * 
2. Nematoxylon 28. OC. au OUR oe ee 
So. Prowtaxites .o0l6 85 29. Cyclopteris (Archzopteris), - 
4 ma Aporoxylon, sic. cee 80.: 0: (Aneimites) oe occ Saws se * 
; meMrmoxylon, ..6..+..2...5 31. C. Brownii, 
4 BereMeORVION. oo cuec es */ 39. C. varia, * 
q 7. Sigillaria Vanuxemii, --_--_ * || 33. Neuropteris polymorpha, __ * 
8. S. palpebra, * || 34. N. Serrulata, - * 
9. Didymophyllum,______.-- 30..N. Dawson, sues oe.co ou 
0. Calamodendron, _._....-- * || 36. N. retorquata, it 
1. Calamites transitionis, _.._| * 37. N. resecta, 
2. C. can Me stage * 38. Spenopteris Heeninghausi, _| * 
3. Asterophyllites scutigera, 39. 8. Harttii, * 
ome WUIONA: oc * || 40. Hymenophyllites curtilobus, | 
ularia laxa, 41. H. obtusilobus, 
: 16. Sphenophyllum antiquam, - * || 42. Alethopteris discrepans, = 
byclostigma, ..._...-..-. 43. Pecopteris serrulata, ------ ma 
. OB WEIN a 44, P. preciosa, 
19. Lepidodendron Gaspianum,| | * || 45. Trichomanites, --_-...-~-- 6 
. L. Veltheimi. . * || 46. llipteris, * 
21. Lycopodites Matthewi, - _ _- * || 47. Psaronius, = 
22. L. Richardsoni,_-----..-- 48. Cardiocarpum,: ....------- * 
me ee VeRONOMT, oo... 2 4st 49. ( 
24. Lepidophloios antiquus, --- * || 50. Antholithes, . 
26. Psilophyton princeps, -- ---| 51. Trigonocarpum. ...=-.--=- 
oes ropustius .......... 
direction in which the facts seem to point, by the following 
general statements :— tees : 
1. Some of the forms reckoned as specific in the ee 
gl 
pnts of structure. The fact that so many Erian and 
ld resul 
_ Struggle for existence.” (4) The elevation of a great expanse 
‘new land at the close of the Middle Erian and the beginning 
+ In the manner illustrated by Hyatt and Cope. 
