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SMITtlSONIAN MISCELLANEOUS COLLECTIONS 



VOL. 82 



Basal area. — The basal area (fig. 29), as here interpreted, is the 

 basal part of the elytra itself and the sclerites which form the con- 

 nection with mesonotum and the mesopleura respectively. The articu- 

 latory elements of the elytra itself are made up chiefly of the pro- 

 jected costa (Co) and subcostal veins (Sco) and the costal (a) and 

 the subcostal heads (b). These heads articulate with the mesopleural 

 clavicola (fig. 16, d). There are also four distinct axillaries (fig. 

 29, axi to 3x4) or pteraliae. The first axillary (axi) partly encloses 



Fig. 27. — Gnathotrichus retusiis Lee. : Left elytron, ventral aspect. 



An, anal; Cu, cubitus; Me, media; Ra, radius; Sc, subcosta; Wl, lateral wing lock; a, 

 dorsal or sutural margin; b, costal margin; c, lateral convexity; d, stridulating scraper; 

 e, apex. 



the tegula and fuses at its apex with the second axillary. The second 

 axillary (axo) articulates at its base with the prealar process (a) of 

 the prescutum. The apex of the second axillary forms a heavily 

 chitinized clamp in which the elytra fits as a tongue. The third 

 axillary (axs) corresponds to Hopkins' fiexor plate. It commences on 

 the internal surface of the second axillary and ends on the external 

 surface of the elytra. It is believed that a sclerite (ax4) projecting 

 from the posterior margin of the tegula is the fourth axillary. The 

 tegula (Te) is well developed, having the form of a hairy pad. 



