INDEX AND GLOSSARY. 



215 



Siliceous, made of flint. 



Silk- worm, metamorphosis of, 143. 



Silurian rocks, lower, 185 ; upper, 

 186. 



Sinuous, bending in and out, xvii. 



Siphonophori, xviii. 



Siren, 177. 



Skeleton, 51, 53. 



Skin, structure of, 99. 



Smell, 36. 



Species, the common name of a 

 thing ; constancy of, 43 ; defini- 

 tion of, 



Spinal marrow, 21. 



Spondyli, 201. 



Sponges not animal, 17. 



Spontaneous generation, 140. 



Standing, 64. 



Stapes, 33. 



Star-fish, metamorphoses of, 146 ; 

 eye of, 26 ; mode of progression, 

 57; reproduction of parts, 126. 



Stigmata, openings in insects for the 

 admission of air, 92. 



Stomach, 73. 



Stratified rocks, 183. 



Stratum, a layer. 



Strobila, 133, 138. 



Structure of the earth's crust, 182. 



Sturgeon, compared with white-fish, 

 148. 



Suctoria, insects talcing their food by 

 suction, xvii. 



Swimming, 69. 



Sylvia sutoria, nest of, 46. 



Systole, the contraction of the heart 

 to force out the blood, 90. 



Tape-worm, reproduction of, 140. 



Tarsus, the ancle. 



Taste, 38. 



Teeth, 79. 



Temperate faunas, 166. 



Temporal, relating to the temples, 

 79. 



Tentacle, the horn-like organs on the 

 head of mollusks, usually bearing 

 the eyes, 28. 



Terebratula, 198. 



Tertiary age, 190, 201. 



Tertiary formation, lower, 186 ; up- 

 per, 187. 



Test, the bristle crust covering the 

 crustaceans, &c. 51. 



Teuthideans, the family of cuttle- 

 fishes, xvii. 



Tibia, one of the bones of the leg, 63. 



Tissues, 13 ; areolar, 14 ; cartilagi- 

 nous, 14 ; osseous, 15 ; nervous, 

 15. 



Tongue, 38. 



Touch, 39. 



Trachea, the windpipe, 93. 



Tracheae, the air-tubes of insects, 92. 



Trias formation, 186, 196. 



Trisfunia, 198. 



Trilobites, 9, 193, xvii. 



Trocholites ammdnius, 193. 



Trophi, organs for feeding, of insects, 

 crabs, &c. 



Tropical faunas, 172. 



Trot, 67. 



Tubulibranchiates, xvii. 



Tunicata, mollusks with a leathery 

 covering 1 , 128. 



Turrilites, 200. 



Tympanum, a drum ; the membrane 

 separating the internal and exter- 

 nal ear, 33. 



Type, an ideal image. See p. 



Ulna one of the bones of the arm, 



59. 



Ultimate, final. 

 Univalve, having a single shell, like 



the snail, 3. 



Vascular, composed of vessels, 99. 



Vegetative life, 20 ; layer, 112. 



Veins, 88. 



Ventricle, a cavity of the heart, 89. 



Vermicular, 76. 



Vertebra, a joint of the back-bone, 

 54. 



Vertebrate, having a back-bone, 3. 



Vertical, in a perpendicular direc- 

 tion, 24. 



Vesicle, a small membranous bag. 

 13. 



Vestibule, a porch ; the entrance to 

 one of the cavities of the ear, 34. 



Vibratile, moving to and fro, 87. 



Viscera, 128. 



Vitelline membrane, 108. 



Vitellus, 108. 



Vitreous humor, 26. 



Viviparous, producing living youns, 

 103. 



Vocal cords, 41. 



Voice, 40. 



Voluntary, under control of the will, 

 19. 



Vorticella, reproduction of, 126. 



