Ch.VI. south AMERICA. 253 



cies very remarkable: the firft is called Choros, 

 already mentioned in our defcription of Lima ; the 

 fecond is called Pies de Burros, afies feet ; and the 

 third Bulgados, and thefe to me feem to preclude all 

 manner of doubt that they were originally produced 

 in that fea, from whence they were carried by the 

 waters, and depofued in the places where they are 

 now found. 



I HAVE examined thefe parts with the clofefl atten- 

 tion, and found no manner of veftige of fubterrancous 

 fires. No calcinations are to be met with on the 

 fuiface of the earth, noV among the Ihells ; which, asl 

 Jhave already obferved, are not intermixed with earth ; 

 nor are there ftones, or any other heterogeneous 

 fubftances found among them.. Some of thefe fhelis 

 are entire, others broken ; as muft naturally happen 

 in fuch a clofe compreflion of them, during fo long 

 an interval of time. This.circumftance, however trifling 

 it may appear to fome, may dekrve the confideracion 

 of thofe who have advanced the notion, that fliells may- 

 be formed in the earth by fubterrancous fires, co-ope- 

 rating with the^nature of the foil. 



The Fie de Burro, has its name from the filli in^ 

 clofed in it, refembling, when taken out, the foot of 

 an afs. This^fifh is of a dark brown colour, firm and 

 hlaceo«s ; it is an univalve, its mouth almoft circular, 

 and its diameter about three inches. The bottom of 

 the fhell is concave within, and convex without. The 

 colour within is perfectly white, the furface very 

 fmooth ; the outfide fcabrous and full of tubercles. 

 Its thicknefs in every part is about four or five lines ; 

 and being large, compad, and heavy, is preferred 

 to all others for making lime. 



The bulgados, in the Canaries called bulgaos, are 

 fnails, not at all differing in their form from the com- 

 mon ; but larger than thofe of the. fame name found in 

 gardens, being from two inches, to two inches and a 

 half in diameter. The fliell is alfo very thick, rough 



on 



