FAMILY MEGACHILIDAE Females of the non-parasitic groups in 6. Hind margin of scutellum produced to this family are most easily recognized by form a carinate and broadly truncate the location of the pollen-collecting scopa lip over-hanging posterior surface of on the venter of the abdomen. Also, the propodeum ...... Anthidiellum (p. 18) Hind margin of scutellum rounded ... front wings, without exception, have but 7 two submarginal cells, and the stigma is 7. Anterior margin of pronotal tubercle small. These are typical "long-tongued" broadly expanded, conspicuously cari- bees, having a greatly elongated and slen- nate, extending along anterior border of der glossa. Segments 1 and 2 of the labial notun1 ......Dianthidi~cw~ (p. 15) palpi also are much elongated and flattened, Pronotal tubercles not broadly expanded, not appreciably produced along anterior with the two apical segments very short. border of notum .............. 8 The galeae of the maxillae are similarly elongated, the maxillary palpi with a vari- 8. Second recurrent vein received within or able number of relatively short segments. very near apex of second submarginal Except for the primitive genus Lithurgus, cell; abdominal terga with entire or the pygidial area is absent, and without ex- nearly entire, transverse, apical or sub- apical, yellow or ivory bands; ocelli rela- ception there are no facial foveae. tively large Hetev-anlhidium (p. 23) KEY TO GENERA Second recurrent vein received consider- ably beyond apex of second submarginal 1. Pygideal area well developed in male, in cell; abdomii~alyellow bands submedian, female represented by a short terminal interrupted medially, not strongly nar- spine; scopa present in female, hind rowed toward mid-line; ocelli extremely tibiae beset with coarse spicules or short small Paranthidium (p. 13) spines ..............Lithurgus (p. 6) Pygideal area absent in both sexes; scopa 9(2). Scopa absent; scutellum with promi- present or absent; hind tibiae relatively nent axillary spines .............. smooth ......................... 2 ................CoeBoxys (p. 192) Scopa present; axillary spines absent 10 2. Body surface usually ornamented with pale integumental maculations; claws 10. Arolia absent; black, usually robust bees in female cleft or with subapical inner ..............Megachile (p. 108) teeth; stigma short, its inner margin Arolia present ................ 11 not much longer than its width . 3 Rody surface other than legs not macu- 11. Basal segment of abdomen with anterior lated; claws in female with at most face broadly concave 12 hasal angles or teeth; stigma elongate Rasal segment of abdomen at most nar- rowly concave or merely sulcate 13 3. Scopa absent; mandibles in male black, or 12. Basal concavity of abdomen with a sharp- if maculated, then clypeus black, at ly carinatc rim Heriqdes (p. 48) least in part ..................... 4 Bas41 concavity not carinate Scopa present; male mandibles yellow Ashmeaclielta (p. 63) maculated arid clypeus entirely yellow - 13(11). Tip of margii~alcell approximate to 4. Margin of scutellum somewhat protuber- costa; mandible of female narrow and ant, propodeum completely vertical, elongate; form slender; color black ... without a dorsal, pitted area ......... ............. prochelosto~na (p. 52) ................ Heterostelis (p. 33) Tip of marginal cell bent away from costa Scutellum not at all protuberant, propo- ................................. 14 deum with a narrow but distinct dorsal area ................ Stelis (p. 35) 14. Color black (in all eastern species) ; form usually slender; notaulices elongate li- 5 (3). Pulvilli (arolia) absent; mandible of ................ (p. female with five or more teeth ........ near Hoplitis 56) .................... Anthidium (p. 9) Color metallic blue or green; form usually Pulvilli present; mandible of female with short; notaulices punciform oval ..... at most four teeth .............. 6 ...................... osmia (p. 69) BEES OF THE EASTERNUNITED STATES, 11 HETERANTHIDIUM LITHURGUS ANTHIDIELLUM PROCHELOSTOMA I I PARANTHIDIUM e9 OSMIA HERIADES - A COELIOXYS ASHMEADIELLA 7%= ANTHlDlUM - Figure 1-Venation of front wing in the Megachilidae. Lithurgus Latreille the total length of the head and thorax. In the North American species, which con- (Fig. 1) stitute the subgenus Lithurgopsis, the Lithurge Latreille, 1825. Fam. Nat. Regne males have aroliae between the claws, but Anim., p. 463. (vernacular). these are inevident in the female. The Type: Andrena cornuta Fabricius. Monob. males are further characterized by having Lithurgug perthold, 1821. In Latreille, Nat. a rather generalized abdomen, with six Fam. Thierr. p. 467. (valid emend.). sternal plates expoaed and only the 7th and Ikthurgopsis Fox, 1902. Ent. News 13, p. 138. 8th retracted. Type: fithurgus apicalis Cresson. Orig. It has been pointed out by Pate (1946, desig. Brooklyn Ent. Soc. Bul. 41, p. 13) that Lithurgus Mitchell, 1938. Psyche 45, p. 146- Berthold's emendation of Lithurge to Lith- 155. (revision). t~rgztsis valid. Lithurgus is a widely distributed group KEY TO SPECIES of rather primitive bees, at least with re- 1. Females ........................... 2 spect to the family Megachilidae. It is Males ............................. 3 unique in this family in having a well de- veloped pygidial area in the male, while in 2, Facial protuberance relatively narrow, projecting uniformly for the entire the female it is represented by a short, api- width .......... gibbosus Smith (p. 7) cal spine. The scopa is well developed, the Facial protuberance much wider, project- tibiae of both sexes are coarsely spiculate, ing much more strongly at each side almost spinose, on the outer surfaces, and than in the central area ............ the proboscis is much elongated, exceeding ................ bruesi Mitchell (p. 8) 3. Labrum with a robust, median, basal tub- laterally, those on the more apical terga be- ercle . gibbosus Smith (below) coming coarser and more sparse; terga 2-5 Labrum with a pair of erect, basal tuber- with white, apical fasciae, these widely inter- cles, median area excavated . rupted on 2 and 3, entire and very dense and . bruesi Mitchell (p. 8) conspicuous on 4 and 5, 6 with a dense cover- Lithurgus (Lithurgopsis) gibhosus ing of coarse, blackish pubescence which near- Smith ly hides the pygidial spine, ventral scopa pale (Frontispiece & fig. 2) ochraceous, sterna with thin, entire, white, apical fasciae, but that on sternum 5 quite Lithurgus gibboszcs Smith, 1853. Cat. Hym. dense and conspicuous. Brit. Mus. 1. p. 147. 9. Lithurgus compressus Smith, 1853. Cat. Hym. MALE-Length 15-16 mm. ; black; face Brit. Mus. 1. p. 147. 8. considerably longer than distance between I/ithurgopsis gibbnsvn Fox, 1902. Ent. News eyes above; eyes rather strongly convergent 13, p. 140. below; face below antennae somewhat swollen Lithurgus gibbnsus Mitchell, 1938. Psyche 45, but not protuberant, quite densely punctate; p. 151. clypeus slightly convex, densely rugoso-punc- tate, median portion of apical margin quite FEMALE-Length 17-18 inin.; black; straight; labrum with a quite robust, median, length of face about equal to distance between elongate spine at base just below margin of eyes above; eyes slightly convergent below; clypeus; cheeks subequal to eyes in width; facial protuberance below antennae promi- face above antennae very closely but rather nant, projecting at right angles from surface finely punctate, punctures quite deep and of face, slightly bowed in facial view; clypeus distinct, quite dense on cheeks throughout; quite flat, shining and sparsely punctate, api- pubescence of head entirely whitish, quite cal margin straight, with a prominant silvery dense around antennae, along inner orbits and fringe; cheeks somewhat broader than eyes; across apical margin of clypeus, rather thin mandibles $-dentate, median tooth more prom- above, quite elongate and copious on cheeks inant than the others; labrum densely ochrace- below; dorsum of thorax densely rugoso- ous pubescent beyond the basal, transverse punctate, finely so on scutellum and over ridge which is emarginate medially; pube- most of scutum, but this becoming somewhat scence of head entirely pale, quite dense around more distinctly punctate anteriorly; pleura antennae and along inner orbits, thin else- quite closely and finely punctate beneath where, rather elongate on cheeks below; punc- rather dense pubescence; propodeum rather tures fine and close on vertex medially, be- smooth, punctures fine and rather shallow coming somewhat more widely separated lat- except in dorsal area; pubescence of thorax erally, somewhat coarser and more distant on entirely whitish, except that there is some the shining cheeks below; dorsum of thorax faint yellowing on scutum and scutellum, dull, densely rugose, finely so on scutellum quite dense and elongate laterally and on and on scutum posteriorly, becoming rather propodeum, largely whitish on legs, quite coarsely aciculate anteriorly; pleura distinctly dense on anterior femora and on the apical punctate, closely and quite deeply so above, segments, as also on mid tibiae; femora and becoming more coarsely and more widely tibiae rather closely but quite distinctly punc- separated but not sparse below; propodeum tate, not to any marked degree aciculate; spurs relatively smooth but rather dull, punctures testaceous; tegulae piceous, rather densely very shallow and obscure; tegulae piceous, pubescent anteriorly and along inner margin, quite smooth but rather dull, not noticeably not noticeably