INDEX 



Aa lava, 300. 



Aar glaci >r, movement of, 150. 



pond on, 148. 



rock flour from, 159. 

 Ablation, 147. 

 Abrasion, glacial, 157-158. 

 Abyssal injection hypothesis of volcanism, 



336. 

 Acadian epoch, 402. 

 Accumulation, mountains of, 352. 

 Acervularia davidsoni, 456. 

 Acid rocks, 329. 

 Acrothele subsidua, 414. 

 Actinocrinus multiradiatus, 481. 

 Actinopteri, 465, 485. 

 Adams, F. D., 59, 258, 388. 

 Adeloblatta columbiana, 484. 

 Aftonian stage, 649, 665. 

 Aganides rotatorius, 483. 

 Agassiz, L., 171. 

 Agates, 78. 

 Agnostus, 412. 

 Agnostus interstrictus, 412. 

 Agriochaerus, 620. 

 Alachua Lake, Florida, 69. 

 Alderney breakwater, England, storm 



wave at, 201. 

 Algae, agents of deposition from solution, 



66. 

 Algonkian, see Proterozoic. 

 Alkaline lakes, 136. 

 Allorisma terminale, 483. 

 Allosaurus, 541. 

 Alluvial cones, 124-127. 



fans, 124-127. 



plains, 126, 127. 



terraces, 128. 

 Altitude, effect on disintegration of rocks, 



32. 

 Amazon River, bores in, 202. 

 Amblypoda, 592-594. 



695 



Ammonites, Carboniferous, 481. 



Mesozoic, 528, 530. 

 Amphibians, Carboniferous, 485-489. 



Mesozoic, 536. 



origin of, 488. 



rise of, 489. 



Tertiary, 624-625. 

 Amphiuma, 488. 

 Amygdalocystites florealis, 430. 

 Amygdaloidal rocks, 331. 

 Anchisaurus, 540. 

 Anchura americana, 528. 

 Angiosperms, effect of introduction on life, 

 568. 



Mesozoic, 568. 

 Animals, mechanical action of, 33. 

 Antarctic glaciation, 171. 

 Antecedent streams, 101, 102. 

 Anticlines, 254, 363. 

 Anticlinorium, 256. 

 Apatite, 688. 



Apiocrinus parkinsoni, 525. 

 Appalachia, in Cambrian, 406. 



Devonian, 455. 



Ordovician, 420. 



Permian, 478. 



Silurian, 440. 

 Appalachian coal field, 474. 

 Appalachian deformation, 477-478, 505. 



peneplain, 116. 

 Appalachian trough, Devonian, 453. 



Mississippian, 469. 



Ordovician, 420. 



Permian, 478. 



Silurian, 439. 

 Ararat, Little, fulgurites on, 34. 

 Archaean, see Archaeozoic. 

 Archaeocyathus rensselaericus, 416. 

 Archaeopteryx, 560-561. 

 Archaeozoic era, 389-392. 



batholiths of, 390, 



