25(5 



PTILOTA : IMAGO EXTERNAL ANATOMY. 



together internally, furnished with a pair of palpi, and 

 covered, in a great measure, by a large horny plate, which 

 is generally termed the mentum. The parts of which this 

 organ is composed are numerous, and the greatest confusion 

 has arisen in the works of authors, as to their nomenclature, 

 owing to the numberless modifications which they undergo, 

 whereby the relative proportions and the consequent rela- 

 tions of the various parts with each other, and with the head, 

 are greatly altered. On examining the under side of the 



head of a beetle, the parts of which this lower lip will be found 

 to consist are, first, a broad horny plate (ch or c 2) articu- 

 lated at its base, and connected at its extremity by mem- 

 brane, with a leathery piece (/ 2), within which arises a tieshy 

 organ (t), occasionally having its anterior angles elongated 

 (t t) : the labial palpi (I p) take their rise between the first 

 and second of these pieces. The first named piece is attached 

 to the head by a horny piece (z), which, although apparently 

 articulated in some beetles (as, for instance, in the cock- 

 chafer, the common Chinese MimeJa, &c.), is immoveable, 

 and forms a portion of the throat or jugulum, but which 

 MacLeay regards as part of the lower lip, and culls it 

 stipes. It is the pitce prebasilalre of Strauss-Diircklieiin. 



