APIS. INSECTS. 357 



B. Labial palpi in the form of a scaly bristle, the first two joints very large com- 

 pared to the last two, much compressed, scaly, with the borders membranous. 



a. Auricles or appendages of the labiura very short, in the form of scales ; mandu 

 bles of the females robust, edged, generally triangular and multidentate ; la. 

 brum as long or longer than broad ; belly of the females commonly furnished 

 with a silky brush. 



2. Dasygastrce. 

 * Body narrow and elongated ; abdomen oblong. 



Gen. CERATINA, CHELOSTOMA, HERIADES, STELIS. 

 ** Body of medium length, not cylindrical ; abdomen triangular or semioval. 



Gen. ANTHIDIUM, OSMIA, LITHURGUS, (Centris cornuta. Fab. ;) MEGA- 

 CHILE. 



b. Appendages of the labium in many long, narrow, and in the form of setae ; man- 

 dibles of both sexes narrow, slightly or not dentated, not edged ; labrum general- 

 ly short, semicircular ; no tuft at the belly nor the posterior feet for collecting 

 pollen ; body glabrous or hairy. 



Parasitical insects ; scutellum of many notched or bidentate. 



3. Cuculina. 



* Labrum longitudinal, either of a long square form or in the form of an elongated 

 and truncated triangle. 



Gen. CCELIOXYS, AMMOBATES, PHILEREMUS. 

 ** Labrum short, almost semicircular or semioval. 

 J" Appendages of the labium much shorter than the- labial palpi. 



Gen. PASITES, EPEOLUS, NOMADA. 

 J"}" Appendages of the labium almost as long as the labial palpi. 



Gen. OX^EA, CROCISA, MELECTA. 



2. First joint of the posterior tarsi dilated at the exterior angle of its inferior extre- 

 mity ; the following joint inserted nearer the internal angle of this extremity than 

 of the opposite angle. 



4. Scdbultpedes. 



A. Maxillary palpi of five or six joints. 



Gen. EUCERA, MELTSSODES, (from Brazil, analogous to the preceding ;) MA- 

 CROCERA, MELITTURGA, TETRAPEDIAS, SAROPODA. 



B. Maxillary palpi of at most four joints ; sometimes none., or of one joint. 



Gen. CENTRIS, MELITOME, EPICHARIS, ACANTHOPUS, genera belong, 

 ing to the New Continent. 



II. Three kinds of individuals ; posterior feet with a depres- 

 sion on the internal side of the legs, and a silky brush on 

 the internal face of the Jirst joint of the tarsi. 



2. SOCIALES. 



I. Posterior legs terminated by two spines. 



Gen. EUGLOSSA, BOMBUS. 



II. Posterior legs without spines at their extremity. 



Gen. APIS, MELIPONA, TRIGONA. 



Gen. APIS, Lin. 



Labium filiform, composing with the jaws a kind of proboscis, 

 geniculate and bent downwards ; first joint of the posterior 

 tarsi large, much compressed ; no spines at the extremity of 

 the last two legs; upper wings with one radial and three 

 cubital cells. 



