HYMENOPTERA — MELLIFERA. 953 
These insects, which in the system of Linnzus formed the single 
genus Apis, are characterised by having the basal joint of the pos- 
térior tarsi dilated into an oblong or subtriangular plate (Planta Kirby) 
(fig. 90. 7., 92. 10. 19, 20.), which is generally hirsute on the inside, 
and provided with instruments for collecting and carrying pollen. In 
some species, however, which are parasitic and solitary, this joint is 
simple, but of the same form (fig. 90. 19. 21.); the jaws are strong, 
these organs being ordinarily employed in the economy of the dif- 
ferent species, and consequently being varied accordingly ; the max- 
ill and labium are elongated, and often transformed into a proboscis 
capable of being folded up several times beneath the head (see 
Jig. 89.), the labium being pilose at the extremity; each of the four 
anterior tibia has a single apical spur, and each of the two posterior, 
a pair, except in the genus Apis. 

Saint Fargeau and Serville, in Eneyelop. Méth. tom. x. 
Saint Fargeau. Hist. Nat. Hyménoptéres, 8vo, 1836. 
Wiedemann, in Zoologisches Magazin (g. Plusia and Exarete. ) 
Klug. Ueber geschlechts verschiedenheit der Piezaten, in Der Gesellsch. Naturf. 
Freunde zu Berlin Magazin, 1807, 1808, 1810. — Ditto, in Waltl Reise 
nach Spanien. — Ditto, in Symbol Physice. 
Disderi, in Turin Transactions, vol. 1i. 
Styles. (eaf-cutter Bees), in Philos. Trans. vol. li. 1760, 
Schiffer. Die Mauerbiene (Megachile muraria), 4to. Regens. 1764; and in 
Abhand. von Ins. 2 band. 
Wartmann. Naturg. der Mauerbiene, in Der Naturforscher, 22 st. 
Latreille. Obsery. sur l’Abeille tapissiére de Réaumur, in Bull. Soc. Philomat. 
tom. ii, and 1799. — Ditto. Observ. sur les Mceurs d'une petite Abeille, in 
Magaz. Encyclop. 1799, tom. iv. — Ditto. Obseryv. sur I’ Abeille parietine 
de Fabr., Ann. du Mus. d’Hist. Nat. tom. iii. 1804, and tom. xiv. 1809, — 
Ditto. Monogr. g. Anthidium Fab., in ditto, tom. xiii. 1809; and in 
Germar’s Mag. 1815. 
Spinola. Memoir on Ceratina albilabris, Ann. Mus. d’Hist. Nat. tom. ix. 
1807. 
Huber. Obsery. Trachusa aurulenta Panzer,in Mem. Soc, Phy. Nat. Hist. Geneva, 
vol. ii. ; and in Bulletin des Sci. Nat. September 1825. 
Guilding. Nat. Hist. Xylocopa Teredo F. Trans. Linn. Soc. vol. xiv. 1824. 
Fonscolombe. Megachile sericans (Guérin, Mag. Zool. Ins. No. 505) Onuwes 
Lithurgus (in Ann. Sci. Ent. France, tom. iii. ) 
Marschall de Beberstein. Apis eriophora, Caucasus, in Mém. Moscow, tom. ii. 
1809. 
Westwood, in Trans. Ent. Soe. vol. ii. p. 112. (g. Mesotrichia. ) 
Fabricius, Savigny (Egypte), Brullé (Morea), Perty (Brazil), Coquebert, Panzer, 
Christius, Illiger, Rossi, Spinola, Jurine, Guérin, Curtis, Griffith (An. KS); 
