54 WM. H. ASHMEAD. 



Labium or tongue very elongate, slender and always longer than the mentum ; 

 two basal joints of labial palpi very elongate, compressed, valvate and 

 very unlike the following, which are minute, the third or fourth joint 

 uniting with the second a little before its apex. 



Hind tibiae with two apical spurs 2. 



Hind tibiae without apical spurs. 

 Sexes three, 2, ?. %>'■> workers with corbiculae, 9 without; maxillary palpi 

 very short, 1-jointed ; labial palpi 4-jointed, with the joints very 

 unequal, the first two long, valvately compressed- ... Fam. I. APID^E. 

 2. First submarginal cell not, or rarely, divided by a delicate, oblique nervure; 

 if at all present, incomplete or indicated by a hyaline streak or ner- 

 vure; sexes two, $,%: hind tibiae in 9 outwardly convex or rounded, 

 never concave ; no corbiculae ; basal joint of bind tarsi in 9 not forci- 

 pateatbase; malar space, except in Psithyridae, wanting or indistict, 



never very large . . 3. 



First submarginal cell most frequently divided by a distinct, but delicate, 

 oblique nervure, rarely indistinct; bind tibiae and metatarsi in 9 

 strongly dilated, outwardly concave (in a single case only convex, but 

 this has a channel along the hind margin Aglse) ; metatarsus in 9 

 forcipate at base; malar space large, distinct. 

 Labium transverse, subtrapezoidal, the clypeus not carinate; body densely 

 hairy; scutellum semicircular, rounded off posteriorly and not pro- 

 jecting over the metanotum; sexes three, 9> £, % ; 9 a "d £ w&* 

 corbiculae, and a dense pollen iferous scopa on hind tibiae and tarsi ; 

 labial palpi 4-jointed; maxillary palpi short, 2-jointed ; tongue not 



extending beyond apex of thorax Fam. II. BOMBIDiE. 



Labrum large, subquadrangular, the clypeus, and most frequently the labrum 

 also, carinate; body most frequently metallic, bare or only slightly 

 pubescent, rarely very densely pubescent Eulema; scutellum large, 

 quadrangular, projecting over the metanotum, the axillae very small : 

 sexes two, 9- V > the 9 with corbiculae, but with the polleniferous 

 scopa on hind tibiae and tarsi very sparse and thin, and confined to the 

 lateral edges; labial palpi 2-jointed ; maxillary palpi 1-jointed; tongue 

 reaching to or beyond the middle of abdomen. 



Fam. III. EUGLOSSID/E. 



'■>. Front wings with two submarginal cells 5. 



Front wings with three submarginal cells. 



Eyes extending to or nearly to the base of the mandibles, the malar space 



wanting or at most not longer than the pedicel 4. 



Eyes not nearly extending to the base of the mandibles, the malar space large, 

 distinct, longer than the pedicel and first joint of fiagellum united. 

 .Marginal cell very long, as long or longer than the three submarginal cells 

 united; body rather densely pubescent; abdomen broadly oval or 

 oblong, flat beneath, convex above; 9 without a polleniferous scopa : 

 % with the eyes frequently strongly convergent above, the genitalia, 

 squama and laciuia always membranous. . .Fam. IV. PSITHYRIDAE. 

 4. Labrum large, free, convex or inflexed. 



Marginal cell not especially long or narrow, rarely longer than the first two 

 submarginal cells united. 



