Microscopical Essays. 



175 



infects have only two antennae ; the onifcus, the pagurus, and 

 aftacus have four ; indeed Fabricius gives fix to the latter * Of 

 the ufe they are to thefe little animals, or the end of the Creator 

 in forming them, we are altogether ignorant : fome writers have 

 conjectured that they were the organs of fmell and hearing ; others 

 have fuppofed that they were appropriated to a feeling more 

 delicate than our own, and fenfible to the lead motion or dis- 

 turbance in the ambient fluid in which they move : feveral in- 

 fects cover their eyes with them when they take their reft. They 

 are characterized by naturalifts under the following names : . 



Setaceous are thofe that, like a brittle, grow gradually taper 

 towards their point or extremity. 



Filiform, thread fhaped, and of an uniform thicknefs. 



Moniliform ; thefe are of a regular thicknefs, but confift of 

 a feries of knobs, like a necklace of beads. 



Clavated, formed like a club, increafing gradually from the 

 bafe to the extremity. 



Capitated; thefe are alfo formed like a club, but the lafl 

 articulation is larger than the reft, fmiftiing with a kind of capital 

 or head. 



Fissiles ; thefe are like the former, only that the head is di- 

 vided into different parts or laminae. 



Perfoliate; 



* Fabricius Philofophia Entomologies, p. tg. 



