104 SMITHSONIAN JtllSCIiLLANEOUS COLLECTIONS VOL. 8l 



{Plf), and two terminal lobes, lacinia (Lc) and galea (Ga), and a 

 five-segmented palpus (Pip). 



The cardo presents an irregular topography on its external surface, 

 and is marked into several areas by the lines of a strong branching 

 ridge on its internal surface (fig. 4oB,r). Crampton (1916) calls 

 the part proximal and posterior to the ridge the juxtacardo and the 

 rest of the sclerite the vcracardo, but the inference that these areas 

 are " divisions " of the cardo is scarcely warranted, since the ridge is 

 clearly a mere strengthening device. The articular point {c^ of the 

 cardo with the cranial margin is a knob on the posterior angle of its 

 base, anterior to which is a long arm to which is attached the apodeme 

 ( loAp) of the promotor muscle (C, 10) . A pit in the distal part of the 

 external surface of the cardo (A, s) marks the site of an internal 

 process on which one of the adductor muscles is inserted (B, iia). 

 The distal margin of the cardo is articulated by a long, flexible hinge 

 line with the base of the stipes, but there are no muscles extending 

 between the cardo and stipes. 



The quadrate stipes (fig. 40 A, St) has a strong plate-like ridge 

 on its internal surface near the inner margin (g), on which is in- 

 serted one of the adductor muscles (E, 12). Crampton distinguishes 

 the body of the stipes as the vcrastipcs, and the flange mesad of the 

 muscle-bearing ridge as the jnxtastipcs. The region of the palpifer 

 (A, Plf) is well separated from that of the stipes by an internal ridge 

 (E, /), but the muscles of the palpus ( //, 18), as well as the muscle 

 of the galea {16). have their origin in the stipes, suggesting that the 

 palpifer is a subdivision of the stipes, and not a basal segment of the 

 palpus. 



The lacinia (fig. 40 A, B, Lc) is borne by the distal end of the stipes, 

 and is capable of flexion anteriorly and posteriorly on an oblique axis 

 with the latter. Distally it tapers and ends in two claws turned in- 

 ward. The lacinia is flexed by a pair of strong muscles arising within 

 the stipes (B, i^^a, 13b), and by a slender muscle (/./) having its 

 origin on the wall of the craniuuL 



The galea (fig. 40 A, Ga) is carried by a distal subdivision of the 

 palpifer, which Crampton (1916) calls the basigalea. In form, the 

 galea (A, B, C, Ga) is an oval, flattened lobe ; its walls are but weakly 

 chitinized. Its inner margin lies against the lacinia, and its outer 

 surface is modeled to fit the outer part of the posterior surface of 

 the mandible, against which it can be tightly closed. The base of the 

 galea is marked on the posterior wall by an internal ridge (E, m), upon 

 which is inserted its single flexor muscle {j6). 



