8 A HISTOKY OF RECENT CRUSTACEA 



not podoplithalmous, and does not apply to others that 

 are. Instead of Podophthalma or Decapoda, Burmeister 

 proposed Thoracostraca. To this, however, the objectiona 

 already urged against Thoracipoda will apply, with the 

 additional one, that the word has a termination which had 

 been already employed in two, and has since been em- 

 ployed in the third and fourth of the higher groups. 

 Some purists correct the word Edriophthalma, in accord- 

 ance with its derivation, into Hedriophthalma. They may 

 correct on the printed page, but who can guarantee that 

 they will have their cherished aspirate pronounced ? 



The stalk-eyed Crustacea are portioned out into fonr 

 sub-orders: 1. The Brachyura, or short-tails, such as the 

 edible crab; 2. The Macrura, or long-tails, such as the 

 common lobster, prawn, and shrimp ; 3. The Schizopoda, 

 or cleft-footed crustaceans, in certain points of structure 

 so near to the prawns and shrimps that at least one author 

 of eminence classes them among the Macrura ; and 4. The 

 Stomatopoda, with feet converging about the mouth, crea- 

 tures abundant in some waters, but rare in those that 

 wash the shores of Great Britain. A fifth sub-order, the 

 Anomura, or irregular-tails, has long been accepted, but 

 modern classification is disposed to distribute its members, 

 which include the hermit crabs and others of very curious 

 habits, between the Brachyura and the Macriira, from 

 which they may be supposed to have respectively diverged, 

 yet without losing all trace of family connection. 



The sessile-eyed Crustacea are at present divided into 

 three sub-orders, the Cumacea, Isopoda, and Amphipoda. 

 The Cumacea seem to have entirely escaped the notice of 

 the ancients, and among the moderns an accurate know- 

 ledge of their singular structure is not too widely diffused. 

 One of the genera earliest brought into notice received the 

 name of Guma, a wave, and from this was formed the de- 

 signation Cumacea for the whole sub-order, which is exclu- 

 sively marine. The Amphipoda, which are common in 

 fresh as well as in salt water, were so named by the French 

 naturalist Latreille, as having feet extending in all direc- 

 tions, their limbs at the same time having much diversity 



