INDEX — GLOSSARY 



Every reference is to the page ; words in italics are names of genera and species. 

 Figures in italics indicate illustrations ; in heavy type, principal descriptions. 



Abdomen, of the crayfish, 275, 276; of 

 the horseshoe crab, 277 ; of trilobites, 

 286, 287. 



Abdominal ganglia, in gastropods, 237. 



AbietiE, 71. 



Absorption, of old skeleton in Crustacea, 

 278. 



Abyssal, depths greater than 100 fathoms ; 

 seas, beginning of, igi. 



Acanthodes, 342. 



Acanthodii, 342 ; fins in, 340. 



A carina, 316. 



Accidents to ancient life preserved in 

 fossils (in the turtle), 366. 



Acorn barnacle, 305. 



Acrania, 322, 323 ; geologic range of, 409 ; 

 notochord in, 323. 



Actinophrys, 03. 



Actinopoda, 93. 



Actinopterygians, 345 ; see Actinop- 

 terygii. 



Actinopterygii, 345 ; fins in, 340. 



Adductor muscle, effect of loss of one 

 upon pelecypod shell, 222 ; of brachio- 

 pods, 182, 183 ; of pelecypods, 20Q, 

 210,211, 214, 221; of phyllopods, 502. 



Adelochorda, 321, 322; geologic range 

 of, 409 ; related to annelids, MoUus- 

 coidea and Echinodermata, 322. 



Age, method of determining age of pele- 

 cypods, 215 ; of pelecypods, 218. 



Agelacrinus, 156-157; A. cincinnatien- 

 sis, 156 ; ambulacra of, 156 ; calyx of, 



157- 

 Aglaspis, 311, 312. 

 Agnostus, 291. 

 Aigialosaurs, 367. 

 Air-breathing snails, 242. 

 Albatross, compared to pterosaurs, 365. 

 Alcyonaria, 129, 131, 135-138. 

 Alcyonium, 128. 



41 



Algae, 35-40, 169; as rock builders, 38; 

 blue-green, 33 ; brown, 36 ; doubtful, 

 40 ; geologic range of, 408 ; in sponges, 

 96; green, 27, 35; lime carbonate in, 

 27; lime secretion in, 38-40; red, 

 27, 37; thermal, 39. 



Alligator, 365 ; brain of young, 372 ; 

 compared to fossil birds, 372 ; com- 

 pared to Ichthyornis, 372. 



Alluvial fan of Newark beds, 6. 



Alternation of generation, in bryophytes, 

 42 ; in Hydrozoa, 1 1 1 . 



Alveolus, of Belemnites, 271, l^jl. 



Amber, 4, 10. 



Amblypoda, 386. 



Amhly stoma, 353. 



Ambulacra, of Agelacrinus, 156; of 

 Asterias, 149; of Caryocrinus, 155; 

 of cystoids, 155, 156; of echinoderms, 

 148 ; of echinoids, 167, 170 ; of 

 Pentremites, 158 ; of starfish, 149. 



Ambulacral grooves, of Asterias, 149; 

 of Pentremites, 158, 158; of starfish, 

 149. 



Ambulacrum, plural ambulacra. 



Amia, 347. 



Ammonites, 263, 272 ; see also Ammonoi- 

 dea; associated with Ichthyornis, 372. 



Ammonitic type of suture, 264, 266, 

 267, 268. 



Ammonoidea, 261, 263-268; as index 

 fossils, 263 ; geologic range of, 263. 



Amnion, 335. 



Amniota, 335. 



Amcrba proteus, 84-87, 83; A. ver- 

 rucosa, 85 ; assimilation of, 86 ; con- 

 tractile vacuole of, 84; digestion of, 

 85 ; excretion of, 86 ; movement of, 

 85 ; nervous system of, 87 ; nucleus of, 

 84 ; reproduction of, 87 ; respiration 

 of, 86. 



