TABLE OF CONTENTS. 



PART IV. MOLLUSKS. 



Page. 



W. MOLLUSKS IN GENERAL. BY ERNEST INGERSOLL. 



205. The Cuttles: Cephalopoda ............................ ....................................... 687 



206. The Sea-snails : Gasteropoda ................................................................... 693 



207. The Wing-shells: Pteropoda ...................... ............................................. 702 



208. The Tusk-shells : Solenoconcha ................................................................ 703 



209. The Bivalves: Lamellibranchiata .............................................................. 703 



X. THE LIFE HISTOEY OF THE OYSTEE. BY JOHN A. EYDER. 



210. Outline Sketch of the Coarser Anatomy of the Oyster .......................................... 711 



211. The Minute Anatomy of the Oyster ............................................................ 715 



212. Sex of the American and European Oysters ........................ ... ........................ 719 



213. New Methods of Distinguishing the Sexes and of Taking the Eggs of the Oyster ................ 722 



214. Rate of Growth of Ostrea virginica: 



215. The Food of the Oysters ..................................... .................................. 729 



216. The Cause of the Green Color of Oysters ....................................................... 735 



217. Local Variations in the Form and Habits of the Oyster ......................................... 742 



218. The Oyster Crab as a Mess-mate and Purveyor ................................................. 744 



219. Physical and Vital Agencies Destructive to Oysters ............................................ 746 



220. Natural and Artificial Oyster Banks ............................................................ 750 



PART V. CRUSTACEANS, WORMS, RADIATES, AND SPONGES. 



BY EIOHARD EATHBUN. 

 Y. OBUSTACEANS: 



221. The Crabs ..................................................................................... 763 



222. The Common Edible or Blue Crab ............................................................. 775 



223. The Lobsters ............. . .................................................................... 70 



224. The American Lobster ......................................................................... 781 



225. The Cray Fishes, Astacus and Cambarng ........................................................ 812 



226. The Shrimps and Prawns ...................................................................... 816 



227. The Mantis Shrimps : Squillidse ............................................................... 823 



228. TheAmphipods ............................................................................... 824 



229. Tholsopods ................................................................................... 826 



230. The Eiitomostracans .......................................................................... 827 



231. The Cirripedia ................................................................................ 828 



232. The Xiphosnra ............................................................................... 829 



Z. WOEMS: 



233. The Annelids .................................................................................. 831 



234. The Leeches ................................................................................... 833 



ZA. THE EADIATES: 



235. Tin' I'.i-liiiiodcrras .............................................................................. 838 



236. The Coelenterates ............................................................................. 841 



ZB. THE PORIFEES: 



237. The Sponges .................................................................................. 843 



238. The Genus Spongiu, and the American Commercial Sponges ..................................... 846 



239. Injurious Sponges ................................ , ............................................ 850 



