THE MOUTH-PARTS OF THE THYSANOPTERA. 27 
But if this is a mandible, what are tlie styliform organs 
which have always been considered tbe mandibles of Thy- 
sanoptera? Two symmetrically developed organs of this 
kind are always present. They do not, however, consist 
of one chitinous segment, as commonly represented, but 
the styliform portion is articulated (movably, I think) 
at its base with a shorter piece, which by ordinary dissec- 
tion comes free with the other. In dissections made with 
greater care these basal pieces are seen to be joined to 
the bases of the palpus-bearing triangular parts. It seems 
probable therefore that the styliform organs are lobes of 
the maxillte, and that the triangular organs are also lobes 
of the same. The fact that the palpi are borne upon the 
triangular parts would indicate that these latter were the 
galeae, and the more slender ones were lacinias. But I 
am not satisfied with my examination of these parts, and 
do not wish to insist at present on more than the proba- 
bility that they are lobes of the maxillse. In position, the 
styliform parts lie above or below the palpus-bearing 
pieces, according to the side from which they are seen, 
and their distal portions pass between the rims at the ends 
of the latter. When dissected free from the other mouth- 
parts, and placed under a cover glass, they appear as rep- 
resented in the figure, the slender pieces being pressed to 
the outside. 
