212 NOTES AND MEMORANDA. 



wliole body is buried in grey sand, excepting the antennae and 

 antenna-plates. It should be borne in mind that if the sand be fine, 

 a shrimp will bury itself absolutely ; digging with its swimmerets, 

 kicking the sand forwards with its chelae, finally raking the sand 

 over its back and gently levelling it with its anteunse, but if the 

 least bit be exposed, the wrasses will find it, in spite of its protective 

 colouration. Shrimps put into the wrasses' tank at night escaped 

 for some days, hence they must retire to the sand before daylight is 

 strong enough for the wrasse to see them. The knowledge of night 

 and day is therefore of paramount importance to a shrimp, as it is 

 not safe for it to hunt until darkness has come. Strangely enough, 

 it seems that this knowledge is not obtained through the eyes, or at 

 all events not entirely through them, for if the eyes be extirpated, the 

 shrimps will bury themselves dui'iug the day, getting up in the 

 twilight and careering about at night just like uninjured shrimps. 

 On one occasion (7 p.m., August 4th) I noticed that the blind shrimps 

 in a tub were lifting themselves out of the sand exactly at the same 

 time as the normal shrimps in another vessel were doing so. If, how- 

 ever, food be thrown in by day, the blind shrimps will get up and 

 hunt for it while the normal shrimps very rarely take any notice. 

 Similarly, a blind prawn will remain in his place all day unless food 

 be thrown in, but comes out and wanders at night. It is a singular 

 fact that a prawn, though blind will often find his way back to his 

 proper place, and stay in it. 



Both prawns, shrimps, StenorJiynchus, &c., find their food almost 

 exclusively by scent, and when blind find pieces of food quite as 

 quickly as uninjured ones. If a piece of worm be put into a small 

 glass sphere with a hole in it, and the sphere is then sunk in the 

 tank, the prawns, &c., will come out of their holes and find it. 

 They do not seem to have any very accurate knowledge of the direc- 

 tion of a scent, but on perceiving it they begin rushing vaguely about, 

 feeling the ground all the way with their chelee. On finding the glass, 

 the first comer will feel inside, pull out the worm, and skip with it to 

 some high place. I have noticed that those which come after gene- 

 rally find the glass in which the worm has been as easily as the worm 

 itself, and they will continue feeling inside in a puzzled way for some 

 time, showing that the scent remains after the worm is gone. (Con- 

 ger, soles, and rockling, which all feed by smell and touch, will all 

 do the same thing.) 



Shrimps are much quicker at finding food than prawns. They 

 hunt with their faces down on the ground like hounds questing, while 

 the prawn hunts with his head held up as usual. If a piece of worm 

 be just buried in sand, a shrimp will dig it out at once, whether blind 

 or not. I have also seen a prawn, after much hesitation, plunge its 



