3850 The Zoologist — February, 1874. 



l^eep Ihem in a living state till the}' are eaten from day to day. 

 They are accordingly brought in baskets measuring eighteen inches 

 long, twelve inches broad, and only two inches deep, and this small 

 thickness enables the shrimps to be well aerated throughout on the 

 journey. I devised this plan, as when they came in high basinets 

 only those at the surface arrived alive. They cost us, in good condi- 

 tion, about a shilling a quart, but if it was necessary to bring them 

 alive, ill water, they would cost at least a guinea a quart ! This 

 system of exposing water to air in a state of exceedingly minute 

 division may be seen in the Crystal Palace Aquarium in a kind of 

 inverse application of the principle, the air as it descends being very 

 finely pulverized in every tank, and all that the water can possibly 

 absorb is taken up. It could not be so finely comminuted and 

 diffused if it were made to ascend, and therefore the ascending 

 plan is a very wasteful one. 



To return to Liraulus. They are brought from America in tubs 

 or boxes containing a layer, two or three inches deep, of wet 

 sand, which is kept moist by having water — sea or fresh water — 

 thrown on it occasionally. Some travelled from New York to 

 Liverpool in a deal-box kept moist by a bladder of water 

 suspended inside it, and in this they again travelled from 

 Liverpool to Hamburg. Some I by accident kept in some badly 

 aiirated sea-water in a vessel with steep sides, out of which the 

 crabs could not climb for air. I removed them, apparently dead, 

 and sent them to the City of Hamburg Museum to be put in spirits, 

 but they revived on a cold damp stone-floor, where their gills 

 became oxygenated, and were brought back to the aquarium, 

 where they lived long. 



At Professor Owen's request, I sent him some notes on the habits 

 of Limulus in captivity, and he has printed my observations with 

 his own in the Linuean 'Transactions' (vol. xxviii. pp. 471 — 472), 

 thus: — 



" The ulterior pair of limbs are not for walking, but exclusively for 

 burrowing. These limbs arc terminated by four long stiff lobes of an oval 

 or leaf shape, jointed at the base, ou the leg, and capable of being opened 

 and closed in a four-radiate manner. When it wishes to burrow, these two 

 limbs are, sometimes alternately and sometimes simultaneously, thrust 

 backwards below the carapace, quite beyond the hinder edge of the shell ; 

 and in the act of thrusting, the lobes or plates on each leg encounter the 

 sand, the resistance or pressure of which causes them to open and fill. with 



