ON CRUSTACEA. 309 



tence, must have seen them under Ibis particular circum- 

 stance. According to the report of the last-mentioned writer, 

 the pagurus, which has for a short time quitted its shell, runs 

 fast, when any danger threatens, back to the place where it* 

 has left it, re-enters it quickly, going backwards, endeavours 

 to close its entrance against the enemy, and defends itself with 

 its claws. According to him, its bite produces for two days 

 the same effect as the sting of the scorjnon ; but the pincers 

 of the pagurus, being similar to those of the other decapod 

 Crustacea, cannot act in a different manner, and like them can 

 produce nothing but a pressure, more or less strong, on the 

 body which they have seized. 



Some authors have spoken of the combats in which the 

 paguri engage for the possession of a shell : it does not always 

 fall to the lot of the conqueror ; for, during the struggle, ano- 

 ther individual has sometimes the address to possess himself 

 of the object in dispute. 



Other Crustacea, which are placed in the same genus, but 

 little known, and some of which perhaps do not belong to it, 

 have no need of shells, and make their retreat in the holes of 

 rocks, in sponges, in the tubes of the serpula3 ; others remain, 

 as is reported, in the sand. :. 



Like the other decapod Crustacea, the females of the paguri 

 cany their eggs under the tail, and attached to small barbed 

 nets, or to the false feet ; but it appears that these oviferous 

 appendages occupy but one of the sides of the tail. Accord- 

 ing to M. Risso, these animals lay eggs two or three times a 

 year, and always approach the sea shore where a collection of 

 little empty shells is accumulated, so that the young ones may 

 choose, as soon as they are born, a suitable retirement. After 

 their first growth, they possess themselves of columbellae, of 

 tupia^, of fresh water shells, which have been carried into 

 the sea ; afterwards, of buccina, of cerithia?, and of rocks. 

 Whether they walk upon the rocks outside the water, or draw 



