New Social Bees WPA7/ 
1917] Cockerell 
near to 7’. lineata Lep., but with yellow markings, and apparently 
distinct. Unfortunately, I do not know the male of lineata; and 
even R. du Buysson, who had a nest full of lineata, found no males. 
There is a good deal of confusion as to what 7’. lineata really is. 
The species I accept as such (from Brazil) is that called lineata by 
Friese. Baker and Ashmead formerly identified as lineata Mexi- 
can specimens of T. frontalis flavocincta Ckll., an insect easily 
separated by the shining mesothorax. Ducke stated in 1910 that 
T. bilineata Say was the same as lineata; but what I have regarded 
as bilineata (e. g. from Mexico, D. F., J. R. Inda) is extremely 
close to T. bipunctata Lep., agreeing in the light patches at sides 
of face. The clypeus of bilineata, as thus interpreted, is highly 
polished; that of bipunctata dullish. 
Trigona atomaria sp. nov. 
Worker: Length about 3 mm.; yellow, including antenne; face 
and front without markings, but vertex with a transverse dark 
band enclosing ocelli; metathorax dorsally pure black; legs yellow, 
hind tibiz (which are not unusually broad) with hind and apical 
margins on outer side broadly brown, hind basitarsi, brown on 
outer side; tegule pale testaceous; wings clear hyaline, nervures 
and stigma pallid; stigma large, with a dusky margin; abdomen 
with black bands on hind margins of segments. Head ordinary, 
abdomen broad. 
Pozo Azul, Costa Rica, June 15, 1902 (M. A. Carriker). A sin- 
gular little species, not close to any other. It may perhaps be 
compared with T. goeldiana Friese, from Para, but the markings 
are wholly different. 
Trigona ferricauda sp. nov. 
Worker: Length about 5.5 mm., with long and ample wings; 
head large but of ordinary shape, black, with clypeus, supracly- 
peal area and lower corners of face (the last obscurely) ferruginous; 
sides of face and cheeks with a dense pale (olivaceous on cheeks) 
pruinose pubescence; front and vertex smooth and shining; mandi- 
bles ferruginous, strongly quadridentate, with also a minute 
tooth between third and fourth, the teeth black; malar space 
short; scape light rufotestaceous, black above at apex; flagellum 
black above, rufotestaceous beneath, last joint bright red above 
