1864] 
889 
face about the antennse thickly clothed with yellowish hairSj the cly- 
peus, vertex and cheeks clothed with black hairs; mandibles very 
stout, carinated above, tip broad, with two or three stout teeth, the 
outer one acute, the others blunt; antennae short, black. Thorax con¬ 
vex above, finely and closely punctured, densely clothed above with 
yellowish-white hairs, beneath with black hairs. Wings subhyaline, 
slightly tinged with fuscous, especially the marginal cell, at the apex of 
the second submarginal cell a faint hyaline spot; nervures black. Legs 
black, clothed with black hairs, the tarsi with fuscous hairs. Abdo¬ 
men convex above, short, subovate, minutely punctured, black and 
shining; on the apical lateral margins of the first and second segments 
above a tuft of whitish pubescence (the surface being apparently rub¬ 
bed, all the segments, in well-preserved specimens, may have their en¬ 
tire apical margins fringed with whitish pubescence); ventral scopa 
short and black. Length 6j lines. 
Hah. —G-reat Slave Lake, British America. One specimen. Coll. 
Smithsonian Institution. 
This may eventually prove to be the female of M. argentifrons. as it 
bears some resemblance to that species. 
Gen. CEEATINA, Latr. 
Head transverse, the ocelli placed in a triangle on the vertex; the lahrum 
subquadrate; the mandibles short and stout, tridentate at their apex. The labial 
palpi four-jointed, the two basal joints elongate, the third and fourth minute, 
placed at the side and near the apex of the second joint. The maxillary palpi 
six-jointed, the three basal joints of about equal length; subclavate, the apical 
joints minute. The superior wings with one marginal and three submarginal 
cells; the second submarginal cell receiving the first recurrent nervure a little 
beyond the middle, the third submarginal receiving the second recurrent ner¬ 
vure also beyond the middle. Abdo^nen clavate.”—Smith, Bees of Great Brit¬ 
ain, p. 193. 
Two species of these little bees are known to me, one of which ( C. 
dupla., Say,) is rather abundant, and is said to excavate the pith of our 
common Mullein ( Verbascum Thapms). Four species have been de¬ 
scribed from Panama. I have not seen any of them. 
1. C. dupla, Say. 
Ceratina dupla, Say, Bost. Jour. Nat. Hist, i, p. 399. (1837.) 
Female ..—^Body dark green, sometimes varying to deep blue, shin¬ 
ing, densely punctured. Head rather large, the face on each side 
