69 



the morrow in the place where you left it the 

 preceding night, and you perceive it higher up, 

 or lower down the current of the river, pro- 

 ducing, with other aquatic families, new effects 

 and new beauties." 



THE PHLOAS, A LUMINOUS WORM. 



This curious animal (Phloas) is of the genus 

 Vermes testacea; shell bivalve, divaricate, with 

 several lesser differently shaped accessary ones 

 at the hinge ; hinges recurved, united by a car- 

 tilage in the inside; beneath the hinge is an 

 incurved tooth. The inhabitants of this genus 

 perforate clay, spongy stones, and wood, while 

 in their younger state ; and as they increase in 

 size, enlarge their habitation within, and thus 

 become imprisoned. They contain a phospho- 

 rous liquor, of great brilliancy in the dark, and 

 which illuminates whatever it touches, or hap- 

 pens to fall Upon. There are twelve species. 



All that we can know with certainty is, that 

 they must have penetrated these substances 

 when very small, because the entrance of the 

 hole in which the Phloas lodges is always much 

 less than the inner part of it, and, indeed, than 



