THE ATLANTIC OCEAN. 185 



are groups of little Barnacles (Lepas), from the 

 size of a pin's head to half an inch in length. While 

 under water, these are incessantly projecting and re- 

 tracting the elegant curled apparatus of cirri with 

 which they are furnished, resembling a plume of 

 feathers; from which resemblance it probably was 

 that the inhabitants of a species found on the Scot- 

 tish coast were asserted to be u of that nature to be 

 finally by nature of seas resolved into geese."*** The 

 purpose of this continual motion of the fringed arms 

 appears to be twofold; first, to make a constant eddy 

 in the surrounding water, and thus bring minute ani- 

 mals within reach, and then to enclose such as are 

 brought in as by the cast of a net, and convey them 

 to the mouth. Crawling on the surface of the weed 

 we may now and then find a nimble little Crab 

 (Lupa), with the shell on each side projecting hori- 

 zontally into a sharp spine. We are surprised at 

 first to find a Crab on the surface of the Ocean, as 

 the species with which we are familiar have not the 

 power of swimming. On endeavouring to procure 

 one for examination, however, we no sooner touch 

 the fragment of the weed with the boat-hook, than the 

 watchful little Crab hurries off into the water, and 

 swims rapidly away out of reach. If we be for- 

 tunate enough to secure one by skilful manoeuvring 

 with the bucket or dip-net, we shall discover a 

 peculiar structure, by means of which these Ocean- 

 crabs are. endowed with the faculty of swimming. 

 In the common Crab, all the feet, except the claws, 

 terminate in a sharp point, but in the present genus 



* Boece, Cosmography of Albioun. Edin. about 1541. 



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