211 



very slender, slightly incrassated towards the apex ; 3 large and much in- 

 crassated, ovate with the apes truncate ; 4 small and slender, contracted in 

 the middle and dilated at the extremities, with the apex straightly truncate. 



Labial jjaljji (PI. VIII., tig. 6, m) subcylindric, small and slender, three-jointed; 

 1 long, cyliudric ; 2 very small and short ; 3 short, like the second, truncate 

 at the apex. 



Labrum (PI. VIIL, fig. 3) suboblong, slightly rounded in front ; epistoma large, 

 suboblong. 



Mandibles (PI. VIIL, fig. 4) bipartite with the apical half forming a strong roundly 

 incurved double hook, and the basal half abruptly incrassated, and furnished 

 on the inner side with a small rounded appendage, serrate on the outer edge. 



MaxilUe (PL VIIL, fig. 5) feeble, bilobed ; outer lobe slender and fiat, acuminate 

 towards the apex, and sparingly furnished with set;e; inner lobe slender, nearly 

 as long as the outer lobe, and armed at the apes with setiform teeth. Stipes 

 robust. 



Mentum (PI. VIIL, fig. 6, j) very large, suboblong, widest at the base, strengthened 

 with broad lateral costae, with all its angles rounded. 



Labium (PL VIIL, fig. 6, k) short, transversely oblong, strengthened with broad 

 lateral costse. 



Lingua (PI. VIIL, fig. 6, 1) rather large, as long as the labial palpi, fan-shaped, 

 with the anterior margin ciliated. 



Pronotiim short, transverse, widest at the base. 



Sciitellum generally large, triangular. 



Elytra entire. 



Wings (PL VIIL, fig. 9) very large, not pedunculated, with strong neuration, the 

 lower primary nerve strongly incurved near the middle of the wing and from 

 thence broadly dilated ; the lower margin of the wings fringed with setiform 

 hairs. 



Abdomen comjjosed of seven segments, of which the sis basal are coriaceous, nearly 

 equal in length, and the seventh subcorneous and longer than the sixth. In 

 S. acaroides, and perhaps in others, there is a deep and broad conical depres- 

 sion on the abdomen, beginning on the fourth segment, gradually increasing 

 in width, and extending to the sides of the seventh. 



Prothorax (PI. VIIL, fig. 2, a) short, with the prosternum carinated, with the carina 

 dilated posteriorly; episterna conspicuous, trigonal; epimera small, partly 

 inclosing the cosal cavities ; coxal cavities large, partly open behind. 



Mesosterniim (PL VIIL, fig. 2, d) very short ; episterna long and narrow ; epimera 

 small and narrow, extending to the cosal cavities ; coxal cavities large, 

 elongate-oval, aln-uptly emarginate at the outer extremity, widely distant from 

 each other. 



Metasternum (PL VIIL, fig. 2, g) very large, extending nearly to the sides of the 

 body, with its posterior margin excavated on each side ; episterna small and 

 narrow, not reaching the coxje ; epimera long and narrow, extending to the 



COXffi. 



Venter composed of five segments ; 1 large and long ; 2 and 3 very short ; 4 and 5 

 large and very long, apical entire. 



Legs anterior (PL VIIL, fig. 8) with the trochanters very short; femora very 

 robust, widely grooved on the under side with the edges of the groove acutely 

 angulated near the middle ; tibiae broadly dilated, widest near the middle, with 

 their outer margin deeply excised near the apes and armed with short spines 

 on the upper angle of the excision ; tarsi robust, three-jointed ; 1 long, sub- 

 cylindric, apparently composed of two amalgamated joints ; 2 much smaller 

 than the first ; 3 elongate ; claws moderate, simple. 

 intermidiate nearly similar to the anterior, but with the femoral groove shorter, 

 and the tibiae simple and less dilated, and armed on the inner side at the apex 

 with a short spur. 



