390 NATURAL ARRANGEMENT OF INSECTS. 



of the earth, and rocks, or in hollow trees : they feed 

 variously ; and it is known that they will prey as freely 

 upon putrid carcases, — disputing their possession with 

 the vulture, — as upon fruits and vegetables; and yet 

 they are esteemed and used as delicate and choice 

 articles of food. Their instinct prompts them, at the 

 period of oviposition, to seek the shores of the ocean, 

 and therein to deposit their eggs ; and this migration 

 they execute in such multitudes, that the land is lite- 

 rally covered with them ; and 'their progress is as direct 

 and destructive as a stream of lava, passing over every 

 thing. Having arrived on the coast, they bathe them- 

 selves, and then deposit their eggs ; and this accom- 

 plished, they again seek their former habitats, — but, 

 of course, in a considerably exhausted state ; and they 

 therefore frequently halt, and repose on their journey. 

 Having regained their domicile, they undergo their 

 moult, which is a critical period in their lives ; and to 

 shelter them from external injury, as they are then 

 soft and sickly, their integument resembling wet parch- 

 ment, they closely shut themselves in their burrows ; and 

 it is now that their flesh is most esteemed. Their eggs, 

 meantime, being recastupon the sand,are speedily hatched 

 by a combination of heat and moisture ; when the young 

 hasten to the adjoining fields, where they gradually ac- 

 quire the strength and size requisite to enable them to 

 undertake their migration to the haunts of their parents. 

 They are chiefly nocturnal animals, migrating and prey- 

 ing at night. It is a remarkable fact, that, although 

 furnished with branchife, their vitality is suspended by 

 immersion in water ; and also that they possess a cavity 

 in the vicinity of their respiratory apparatus, which serves 

 as a reservoir for the water requisite to keep those organs 

 constantly moistened. The neighbouring Gelasimus is 

 singular for the excessive developement of one of its 

 claws, which is sometimes larger than the whole of the 

 rest of the body, and serves it to close the aperture of its 

 burrow, when it has retired. The habit it has of raising 

 this, as if calling, has procured it its specific name of G, 

 vocans. The genus Nauiicoyrapsus consists of small 



