122 



ENTOMOLOGICAL NEWS. 



[October, 



ing part of the maxilla and is often furnished with teeth or spines ;' ' 

 sometimes it bears a terminal joint — the digitus. As often hap- 

 pens in the case of other appendages, the sutures separating con- 

 tiguous joints of the maxilla become obliterated and the joints 

 unite. In such cases the maxilla appears to be composed of a 

 less number of joints than here described. Careful comparative 

 study alone will show where such obliterations and unions have 

 taken place in any one insect. 



Unlike the labrum, the labium, or lower lip, is quite complex. 

 It so much resembles the maxillae as to have received the name 



of second maxillce. The labium is to 

 be regarded as a pair of appendages 

 united to each other on the middle 

 line of the body. A comparison of 

 fig. 8 with the right side of fig. 9, 

 will show the correspondence between 

 a maxilla and half the labium, the 

 homologous parts being lettered alike 

 in the two figures. The basal joint 

 .of the labium is \\\^subnienUim, which 

 articulates with the gula; it is a single 

 median piece and corresponds to the 

 united cardos of the right and left 

 maxillae. The second joint, also a 

 single median piece is the rnentutn^^ 

 corresponding to the united stipes of 

 the right and left maxillae. At each 

 outer apical angle of the mentum is 

 the palpiger^ the homologue of the 

 palpifer. The palpiger bears the la- 

 bial palpus, whose similarity to the maxillary palpus cannot be 

 mistaken. The joint marked e in fig. 9 is apparently unnamed; 

 it corresponds to the subgalea, and bears two lobes, an inner (^) 

 \h&glossa, and an outer (/) \h^ paraglossa, corresponding to the 

 lacinia and galea respectively. Excepting the submentum, men- 

 tum and labial palpi, all the remaining parts of the labium con- 

 stitute the ligula. Few insects have the joints of the labium so 

 distinct as the Black Cricket (fig. 9). Thus in the labiu m of the 



* Some confusion exists as to the use of the term mentum. By some it is applied to the 

 part described above as the submentum, in which case that described above as the mentum 

 receives the name o{ hypoglottis. We have followed Comstock and Packard in the text. 



Fig. 9. Ventral side of labium of 

 Black Cricket {Gryllus). 



a, submentum ; h, l>, mentum ; c, 

 palpiger; d, three-jointed labial pal- 

 pus ; e, (unnamed, = subgalea) ; /, 

 two-jointed paraglossa ; g, glossa. 

 The parts of the labium are here 

 marked with the same letters as the 

 corresponding parts in fig. 8. The 

 mentum is one piece, but there is a 

 line across it. The glossae are not 

 two.jointed, as the figure might 

 seem to show, what looks like a 

 terminal joint is a thin, membranous 

 portion. The suture between each 

 palpiger and mentum obliterated. 



