156 AMERICAN HYMENOPTERA. 



about in the narrowest part of the vertex. Third antennal segment 

 much longer than the fifth, not greatly shorter than the fourth and 

 fifth together; the fifth somewhat longer than the fourth. 



Thorax. — Dorsum covered with dark cinereous pile (this pile is a 

 mixture of black hairs and mostly shorter and finer white pile or down); 

 a considerable area on the center of the disc naked. Pleura and 

 sides of median segment entirely dark. 



Addume ft. —Dorsum: segment one black; segment two black, but 

 with apical margin bearing white hair. Segments three, four and five 

 covered with white pile ; segment six dark in the middle, but with 

 white hair on the sides. Venter mostly dark, but with fringes of apical 

 margins of most of the apical segments more or less white or whitish. 

 Epipygium with a very slight longitudinal median carina on very 

 apical portion. Hypopygium without a median carina. 



JVings.— Very dark. With strong violaceous reflections. The trans- 

 verse median vein of the fore wings forming nearly a right angle with 

 both the median and the anal vein. 

 Le^s.— Pile entirely dark. 



JVorker.— Like the queen, but the clypeus rather more coarsely 

 punctate. 

 Ma/e. — Unknown. 



Dimensions.— Length : queen, 20 mm. to 26 mm. ; worker, 13 mm. 

 to 15 mm. Spread of wings: queen, 46 mm. to 50 mm.; worker, 

 about 34 mm. 



The typical queen is here described from two specimens 

 from Boquete, Chiriqui. There are specimens before me 

 showing the following variations : 



Color Variant i.— Like the typical queen, but with no white hair on 

 the apical margin of the second dorsal abdominal segment. One speci- 

 men, from Boquete, Chiriqui. 



Color Variant 2. — Like the typical queen, but with the second dor- 

 sal abdominal segment entirely black and with the basal portion 

 of the third segment clothed with black pile. One specimen, from 

 Colombia. 



Color Variant J.— Like Color Variant 2, but with the third dorsal 

 abdominal segment entirely black, except the very apical margin. 

 One queen from Chiriqui and one from Ecuador. 



Color Variant 4. — {= vogti H. Friese). Like Color Variant 3, but 

 with the third dorsal abdominal segment entirely black and with the 

 basal half of the fourth segment also covered with black pile. One 

 queen, from Bolivia (Tarata). 



Color Variant 5 . — Like the typical worker, but with all but the last 

 two dorsal abdominal segments covered with entirely black pile. One 

 worker, from Bolivia (Tarata). 



Color Variant 6.— Like Color Variant 3, but with the short, fine pile 



