Wood-lice, 150. Woodpecker, California, 356; ivory-billed, 355; red-headed, 355. Woodpeckers, 354. Wood-rat, 391. Worm, army, *211. Worms, 127; life-history and habits of, 133; classification of, 135; marine, *134. _Xiphias gladius_, 285. Yellow-hammer, *355. Yellow-jackets, 217. Yellow-shank, 349. _Zenaidura macroura_, 351. Zoogeography, 436. Zooids, 98. Zoology, a first course in, 3; defined, 3; divisions of, 2; systematic, defined, 3. Zoophytes, 92. Transcriber's Notes: Obvious punctuation and spelling errors have been fixed throughout. Inconsistent hyphenation has been left as in the original text. There is no figure 27, the original text goes from figure 26 to 28, left as in the original text. Page 245: There is no closing parenthesis for the sentence starting "(Where the typical...". End of the Project Gutenberg EBook of Elementary Zoology, Second Edition, by Vernon L. Kellogg