Xviii TABLE OF CONTENTS. 







PART IV. MOLLUSKS. 



Page. 



W. MOLLUSKS IN GENERAL. BY ERNEST INGERSOLL. 



205. The Cuttles: Cephalopoda 687 



206. The Sea-suails : 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 OYSTEK. BY JOHN A. RYDER. 



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. Eate of Growth of Ostrea virgiuica: 



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. Katural and Artificial Oyster Bank's 750 



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



BY RICHARD RATHBUN. 

 Y. CRUSTACEANS : 



221. The Crabs 763 



222. The Common Edible or Blue Crab 775 



223. The Lobsters 780 



224. The American Lobster 781 



225. The Cray Fishes, Astacns and Cambarus 812 



22C. The Shrimps and Prawns , 816 



227. The Mantis Shrimps: Squillidaj 823 



228. The Amphipods 824 



229. Thelsopods 826 



230. The Entomostracans 827 



231. The Cirripedia 828 



232. TheXiphosura 829 



Z. WORMS: 



233. The Annelids 831 



234. Tho Leeches 833 



ZA. THE RADIATES: 



235. Tho Echhioderms 838 



236. The Coelentcrates 841 



ZB. THE PORIFERS: 



237. The Sponges 843 



233. Tho Genus Spongia, and the American Commercial Sponges 846 



239. Injurious Sponges 850 



