24 DURyfA, ITS PEOPLE AND PRODCCTIOXS. 



Older THOEACICA. 



Famili/ Lepadidae. 



This family emliraces the pedunculate eimpcds, the stalked Barnacles, or ' gnose 

 barnacles ' as they were sometimes called, from the ahsurd idea that they produced 

 the ' bai-naclo Goose.' The leathery stalk or ' peduncle ' by which they atlhero to 

 ships' bottoms or floating timber, is formed by " a modification of the larval 

 antenna;." 



Faintly Balanidae. 



The sessile cii-riped, or common Barnacles are contained within a conical multi- 

 valve shell, closed by an opercailnm, composed of four pieces. The whole shell has 

 a cellular and oi'ganized te.xture, and by the chambered structure of its walls, is said 

 to have given the idea to shipbuilders of the double skin or cellular arrangement of 

 iron plates in a ship's hull or a bridge girder, which so materially adds to their 

 strenglli, with a niiuimnm amount of material. The cement by which the animal 

 fixes itself to its selected site, is secreted by an organ, which Darwin has shown to 

 be a moLlified portiou of the ovarian tube. 



Sub-class EPIZOA. 



These animals are external parasites of grotesque form, on fish and other maiine 

 pnd freshwater auimals. Their mouth is suctorial, they ])ossess no respiratory 

 organ, and the females carry two external and pendant ovisacs. There are two 

 orders, Siphouostoma and LeruiEodea. 



Sub-class ENTOMOSTRACA. 



Body protected by a carapace composed of one, two or more plates or valves. 

 Limbs jointed, setil'erous. Sexes separate, but agamic reproduction (^Parthenogenesis) 

 is " not uncommon " (Pascoe). They arc mostly freshwater animals of minute size. 

 There are five orders, Copepoda, Ostracoda, Cladocera, rhijlhipoda, and Xiphura, 

 besides the extinct order of Trilohites, which so swarmed in ralKcjzoic seas. 



The order Xiphuia embraces the king crabs {Limultis), one or two species of 

 which are common on the Arakan coast (Z. roliindicaudatus, Edw., and L. Moluo- 

 canus, Edw.). 



Sub-class EDRIOPHTJTALMA. 



This sub-class comprises three orders, Lasmodipoda, Amphipoda, and Isopoda. 



The common ' zvood louse,' monheg pea, or sow-bug ( Onisem) is an example of 

 a terrestrial Isopod. uFga spongiophila resides inside the beautiful siliceous sponge 

 Euplectella aspergillum, within which its cxuvia; may generally be noticed. " Bopyrus 

 si/iiillarum is found commonly under the skin of prawns, Liyio2)e is a parasite on 

 I'eltogaster, itself a parasite ! " (Pascoe). 



is^'umberless animals of this interesting sub-class occur in Burma, but they all 

 await the coming " vates sacer," who is to bring them to notice and record their 

 manners and develo])ment and names. A fund of curious information regarding 

 them is contained in Van Beneden's " Animal Parasites." 



Sub-class PODOPnTHALMA. 



Order STOMATOPODA. 



Branchiic external, cither beneath the abdomen, or attached to the thoracic 

 legs, llarcly rudimentary or wanting. Carapace generally thin, and covering the 

 whole (or ])a'rt) of the thorax. Abdomen elongate and ending in a "natatory tail." 

 The ' gnatliites ' are confined to a pair of mandibles, two pairs of maxilla;, and a pair 

 of foot-jaws whicli are sometimes ruilinieutaiT, or ai'e connected, as well as the seven 

 succeeduig pairs of limbs, with natatory feet (Pascoe). 



