THE HEAD. 53 



each other as well as to the head and labium by means of soft liga- 

 ments ; the lowest, the HINGE, (cardo, PI. III. f. 16 and 17, 1> 1, or 

 the BASE, pars basalts; according to Straus, branche transversale,) 

 is narrow, thin and transverse, and articulates with the throat, forming 

 a right angle with the one that follows it, which is the STALK (stipes, 

 piece dorsals of Straus, 2, 2 of the same figure), and is thicker, stronger, 

 and larger, and above somewhat horny, but beneath softer and mem- 

 branaceous. Closely attached to this is the third piece, which is a 

 corneous scale, at the anterior margin of which the palpus is inserted 

 (thence called squame palpiftre, by Straus), and which forms beneath 

 the case or covering of the maxilla. The fourth piece (the same plate 

 and figure, 4, 4) borders upon the two preceding, and is completely 

 horny, hooked, its interior margin concave, or, as well as the stalk, 

 covered with short stiff bristles. It is called the MAXILLARY LOBE 

 (lolus maxillae, intermaxillaire of Straus), from its more generally 

 taking the appearance of a superior appendage of the stalk. In many 

 insects, particularly the Hymenoptera and coprophagous Petalocera 

 among the beetles (for example, Copris, Aphodius), it is a simple, 

 variously formed, flat, coriaceous scale, with its margin beset with short 

 hair; in others, as among the Capricorn beetles (Lamia, Cerambyx), 

 it is thicker, and more solid and compact, and is divided into a harder, 

 INTERNAL (lobus internus}, and more membranaceous, EXTERNAL 

 LOBE (lobus extemus). This exterior lobe is the same organ which in 

 the Orthoptera covers the internal lobe like a cap, and then takes the 

 name of HELMET (galea, PI. III. f. 17, 5 of Cychrus, PI. IV. f. 2, 5 

 of Copris}. In many insects it is wanting ; in other instances it occurs 

 as a two-jointed filiform appendage, and this is then the second internal 

 maxillary palpus, as already Illiger * very correctly indicated. It is 

 exactly where the lobes border upon the stalk that the maxillary palpi 

 are also inserted. 



The underlip, or LABIUM (plainly labium, or labium inferius), which 

 is that organ that assists to close the orifice of the mouth from below 



O 



(PI. III. f. 12 and 13, Q). It consists of two chief parts, each of which 

 may be considered as a separate organ ; these are, 



The CHIN (mentum, PI. IV. f. 3 and 4, A, A), a thin, sometimes trian- 

 gular, sometimes of the shape of a segment of a circle, or trapezoidal 

 corneous plate, deeply emarginated upon its anterior side, and con- 

 nected, like the upper lip, to the clypeus, by means of a membrane, 



* Sec Kaefer Preusscns, 1 Vorrcdc, p. xxxvi. note 15. 



