1890.] 

 {e, fig. 7)- 



ENTOMOLOGICAL NEWS. 



121 



Fig. 7. Typical arrangement of mouth parts. 

 Under side of head of Tiger-beetle {Cicindela). 



a, gula ; i, b, gense ; c, c, compound eyes ; d, front 

 margin of labrum ; e, e, e, labium; /, mandible, 

 showing four teeth ; g, four-jointed maxillary pal- 

 pus : h, two-jointed galea ; /, lacinia ; k, four-jointed 

 labial palpus \ e,h and i, are all parts of the maxilla. 



Between the labrum and the labium are two pairs of 



jaws whose normal move- 

 ment is horizontal, not 

 vertical, as in the back- 

 boned animals. The up- 

 per (dorsal) pair — nearest 

 to the labrum — are the 

 mandibles {d, fig. i ;/, fig. 

 7), the lower (ventral) 

 pair are the maxillce {g, 

 h, i, fig. 7). 



Such a typical arrange- 

 ment exists in the biting 

 insects, as in beetles, crick- 

 ets, grasshoppers, etc., 

 and is shown in fig. 7. 

 The labrum usually consists of a single median piece, hinged 

 by its hind or upper edge to the clypeus, by which it may some- 

 times be concealed. 



Next below the labrum are the mandibles. 

 Usually they are one-jointed, and have a cut- 

 ting edge on the inner side. This cutting 

 edge may either be entire, i.e., unbroken, or 

 toothed. 



On the ventral side of the mandibles are 

 the maxillae, which are usually very compli- 

 cated. Each maxilla (fig. 8) consists of a 

 number of joints. The basal joint is the cardo 

 or hinge, the second is the stipes ox footstalk. 

 The palpifer, ox palpics -bearer, is a joint situ- 

 ated on the outer side of the stipes; as its 

 name indicates, it bears a conspicuous one- to 

 six-jointed palp — the maxillary palpus. On 

 the inner side of the stipes is another joint, 

 the S7ibgalea, or helmet- bearer. The subgalea 

 bears two joints, the galea, or helmet, and 

 the lacinia, or blade. The galea and lacinia 

 are each directly attached to the subgalea. 

 The galea is also called the outer, upper, or 

 superior lobe of the maxilla, while the lacinia is the inner, or in- 

 ferior lobe of the maxilla. The lacinia ' ' is the cutting or chew- 



Fig. 8. Ventral side of 

 left maxilla of Tiger- 

 beetle {Cicindela). 



a, cardo; b, stipes; c, 

 palpifer ; d, four-jointed 

 maxillary palpus; e, sub- 

 galea ;/", two-jointed ga- 

 lea; g, lacinia; h, digitus. 

 The suture between the 

 subgalea and the lacinia 

 is obliterated. The fig- 

 ure gives the galea the 

 appearance of being at- 

 tached to the stipes ; its 

 real attachment is to the 

 subgalea, as stated in 

 the text. 



