WILLIAMS: LARRID^ OF KANSAS. 129 



Maxillse. (PI. XXIII, figs. 7, 9 and 10.) The maxillae closely 

 appre.'^s the labium on either side. They are of rather compli- 

 cated structure, in that they are composed of a number of 

 separate sclerites. As with the same structure in the honeybee 

 (Apis), the distal part in Tachytes is considerably shortened, 

 though, if anything, more complex in the wasp. 



Loinim. The lorum, which is conspicuous enough in Apis and 

 Bomhus (among others), could not be made out with certainty 

 here. It is possible that each loium is lepiesented in Tachytes 

 by that broad upper inner poition of the cardines which is here 

 thin and less heavily chitinized than the lower part, though it 

 is in no wise separated therefrom. (See pi. XXIII, fig. 9, N 

 and C.) 



Stipe. (PI. XXIII, figs. 7, 9 and 10, S^.) Articulated to the 

 distal end of each cardo is the stipe, which comprises the larg- 

 est portion of the maxillse. Figure 9 represents an inner view 

 of one of the maxillse ; it will be observed that the stipe is 

 heavily chitinized and composed of several pieces. Near the tip 

 of each stipe arises the large six-jointed maxillary palpus. 



Galea. (PI. XXIII, figs. 7, 9 and 10, MX.) The large blade- 

 like galea of the honeybee is here represented by a short, stout 

 lobe articulated to the stipe. It is armed with stout as well as 

 with fine hairs. 



Lacinia. (PI. XXIII, fig. 9, L.) Arising from a spur of 

 chitin on the inner side of the galea, near its distal extremity, 

 is a well-formed, curved lobe, which would seem to represent 

 the lacinia. When in position, each of these lobes is seen to 

 overlie the more basal of the two dorsal pairs of chitinized 

 lobes or scales of the labium. (See pi. XXIII, fig. 8, k.) Mac- 

 Gilliviay (Ann. Ent. Soc. Am., V, No. 3, 231-8; 1912) de- 

 scribes and illustrates the lacinia in several groups of Hymen- 

 optera, where, as in Tachytes. it consists of a thin pilose lobe 

 far smaller than the galea. The inferior, distal edge of the 

 stipe and the basal portion of the galea are thin and flap-like 

 (fig. 9). 



Labium. (PI. XXIII, figs. 7, 8 and 10.) Commencing from 

 its base, the labium is composed of the submentum (SMt) ; 

 mentum (M) ; and the ligula, which comprises the fused 

 glossae (GL) , the paraglossse (PGL) , and several small sclerites. 

 The submentum is a small, delicate, V-shaped sclerite lying in 



