I06 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 8l 



i6. — Flexor of the galea (fig. 40 B, E). — A large muscle arising 

 mesally in base of stipes, external to lacinial muscles and depressor of 

 palpus; inserted posteriorly on ridge (E, u) at base of galea. This 

 muscle probably flexes the galea forward and inward, the point of flex- 

 ion being at the base of the subgalea. 



//. — Levator of the maxillary palpus (fig. 40 B, E). — Origin in 

 median basal part of stipes ; insertion on dorsal margin of basal seg- 

 ment of palpus. 



18. — Depressor of the maxillary palpus (fig. 40 B, E). — Origin on 

 inner edge of stipes; crosses anterior to muscle of galea {16) to in- 

 sertion on ventral margin of basal segment of palpus. 



If the basal segment of the palpus (fig. 35 A) corresponds with 

 the trochanter of the leg (fig. 34 B, Tr), then muscles ij and iS 

 represent the levator and depressor of the telopodite (fig. 34 A, 0, 

 Q) arising in the coxal region of the leg base (LB). 



ip, 20, 21, 22. — Muscles of the maxillary palpus (fig. 40 B). — A 

 single muscle for each segment, the first (ip) a levator of second seg- 

 ment, the second {20) a productor of third segment, the third (21) 

 a depressor (adductor) of fourth segment, the fourth {22) a reductor 

 of terminal segment. 



The joint between the third and fourth segments of the palpus 

 apparently represents the femero-tibial flexure of a leg (figs. 34, 35 

 A, ft), the two small basal segments of the palpus being trochanters. 



THE LABIUM 



The labium of the grasshopper (fig. 40 D) is simple in construction, 

 and typical of the labium of biting insects, except in the reduction of 

 the glossae. It consists of a largei submentum (Smt) with the elongate 

 basal angles loosely attached to the posterior margin of the cranium 

 behind the roots of the posterior tentorial arms (C, /). The mentum 

 (D, Mt) is broad, with imperfectly differentiated palpus-bearing 

 lobes, or palpigers (Pig), at the sides of its base. On its ventral 

 margin the mentum bears a pair of large flat lobes, the paraglossae 

 (Pgl), with a pair of rudimentary glossae (Gl) between them. Each 

 palpus is three-jointed. 



At the base of the anterior surface of the mentum, where the wall 

 of the mentum is reflected into that of the hypopharynx (fig. 41), 

 there is a small, median, oval, cup-shaped depression into which opens 

 the duct from the salivary glands (SID). A small prominence on the 

 base of the hypopharynx fits into the salivary cup and apparently 

 closes the latter when the labium is pressed against the hypopharynx. 



