ANALYTICAL INDEX. 277 



CHAPTER III.— continued. 



The Cancer mmnas kill and devour one another, . . page 145 



Crabs and Lobsters eagerly sought after as food, . . ib. 



Imported from Norway to the London market ; and some of the Wes- 

 tern Isles are said to yield 60,000 annually, . . 146 



None but rocky coasts are frequented by Lobsters and Crabs, ib. 



The common Crab and Lobster only used for food in Scotland, — 



not so in the Adriatic, .... ib. 



Some genera so peaceable and inactive, that many specimens are 



overgrown with marine vegetables, . . . ib. 



Progeny of a single Crab, spared for two seasons, would probably 



satisfy 10,000 people, . . . . 147 



The sexes distinguished by the shell, . . . . ib. 



The roe adheres to the shell of the female until the fcetus bursts the egg, 148 



A few tribes of Crustacea discharge the ova through long tubes, ib. 



Most Crustacea undergo great changes in their progress to maturity, ib. 



An error to imagine that animals protected by a hard integument 



undergo no alteration with the loss of life, . . 149 



Habits of the crustaceans extremely diversified, , . ib. 



Death simulated to escape danger, ... ib. 



The integument of some is horny or coriaceous, . .150 



The crustacean tribes treated of divided into three portions, ib. 



PART I. A. — Decapodes, ten-limbed, short-tailed Crabs, — Brachyuri, ib. 



§ 1. Cancer m^nas, — The Shore or Harbour Crab, . . ib. 



Its form and organs, ..... 151 



Crustacean class compared to insects, . . . . ib. 



Dr Milne Edwards, . . . . . 152 



Principal divisions not more than two in the crab, . . ib. 



Green the prevailing colour, .... ib. 



Habits and disposition, ..... 153 



Food, ....... ib. 



External integument an indurated shelly covering, . . 154 



Occurs of all different dimensions, .... ib. 



At certain seasons the limbs full of flesh, . . . ib. 



Acquires a new shell when the old is insufficient, . . ib. 



The change effected again and again, .... 155 



Specimens about to exuviate usually dull, heavy, and inactive, 156 



The animal escapes from the hind part of the shell, . . ib. 



Specimen from Blackness Castle — its exuviation, . . 157 



Became very tame — something like memory demonstrated, . 158 



Exuviation verified by another specimen, . . . 159 



Female spawned after eighteen months, . . . 161 



b 



