103 



brought to me on the 20th July, 1855 ; the ova were bright green, 

 and the animal of a cream colour. This specimeu was dead wheu 

 exammed. 



The subject of the present paper was brought to me alive by my 

 dredger on the 21st February in this year, aud lived three weeks. 

 It was dredged in Weymouth Bay, near the month of the harbour. 

 The colour in this hving specimen was very different fioui that of 

 the dead specimens I had previously obtained. When first brought to 

 me, the whole animal was a Ught greenish-drab, irregularly and thinly 

 sprinkled with pure white stars ; the carapace and covering of the 

 abdomen were ahke transparent, and the intestines could be easily 

 seen beneath. I could also detect the breathing apparatus placed on 

 each side at the back of the mouth ; the movement was similar to 

 that of a long rope when gently waved at one end. After a few days' 

 confinement it changed colour, five or six broadish bands of a lovely 

 rose colour appeared, the bands of colour being restricted to the back 

 portion of each segment of the body ; the tail also changed to the 

 šame rosy hue, in the course of two or three days the animal again 

 assumed its original colour. I have noticed this change of colour in 

 many of the Palcemonidce and CrangonidcB, and I believe it to arise 

 from the transparency of the cuticle enabling any change in the body 

 itself to be seen through it, and that the change of colouring of the 

 body is occasioned by fear or some instinct. In all the specimens of 

 Niką I have obtained the shell is soft as in a new-moulted Prawn, and 

 in piercing them with a fine pin for preserving, the shell bends before 

 it. Is this of any value as a generic character ? M. Milne-Edwards 

 says they resemble ^<Aa«as "in possessing but a small rostrum ;" 

 they also resemble them in their mode of locomotion, as they then 

 carry the external pedipalps and first pair of feet extended before 

 them in a line with their body ; their movements are also slow and 

 deliberate, and they appear to progress by vvalking and not by 

 swimming ; when alarmed they shoot backwards by striking forward 

 with their tail, as is the habit of all the long-tailed Crustaceans. 



I now proceed to lay before you the Information I have obtained 

 as to its habits. 



I may assert that Niką is essentially a burrowing genus. I wa6 

 not prepared to find it so, as I considered its slender limbs and its 

 prominent eyes but ill-adapted for the purpose ; however, we live 

 and learn, and I have learned that practice is far better than theory ; 

 had I relied on the latter I should have insisted that Niką edulis was 

 not a burrower. 



In accordance with a plan which I have formed of attempting to 

 study the habits of any of our rarer marine animals I may have the 

 good fortune to meet with, I placed my prisoner in a vase with ą 

 few weeds and some pebbles, that being the nature of the groimd on 

 which itwas dredged; 1 left it in this vessel for two days, and found 

 out it was not at home, and, in fact, that a pebbly bottom was not 

 its choice. I therefore removed it to a large earthenvvare pan in 

 which I had previously placed a few weeds, having filled it also to 

 the depth of three inches with coarse gravel ; I then left it for an 



