HENRY J. FRANKLIN. 155 



The form horhdans indicates a marked variation, on the 

 part of robzistus, toward volucelloides, with which it is closely 

 allied. 



Nigrothoraciais appears to belong in the synonymy of 

 ecuadorius, but eaiadorius may, in reality, be a variety of 

 robusttis. If ecuadorius is a variety of robiistus, it gives addi- 

 tional evidence that robiishis grades strongly toward vohi- 

 celloides. 



Ridocaiidatus may be a variety of robustus, but, because of 

 its color characters, I suspect it of having affinities with 

 opifex. 



Steinbachi is probably a valid variety of robustus. 



Volucelloides is, beyond question, the closest relative of 

 robustus, and it may, indeed, be only a subspecies of it. The 

 yellow pile of this species varies in shade from deep straw- 

 yellow to very pale straw color. 



Bouibus (Bombias) volucelloides Grib. 

 Bojubus volucelloides Gribodo, Bull. Soc. Ent. Ital., XXIII, 1891, p. 

 119, 9. 

 sp. Whymper, Trav. Among Great Andes Equat., 1892, p. 



356. 

 volucelloides Gribodo, Bull. Soc. Ent. Ital., XXV, 1893, p. 

 266, n. 14. 

 Dalla Torre, Cat. Hym., X, 1896, p. 563. 

 leticomelas Crawford and Swank, Can. Ent., XXXV, 1903, p. 



268, 9 a . 

 vogti Friese, Zeitschr. f. System. Hym. und Dipt., Jahrgang 



III, Heft 4, 1903, p. 254, n. 3, 9 S . 

 volucelloides Crawford, Trans. Amer. Ent. Soc, XXXII, 

 1906, p. 157 (name omitted by mistake). 



Type locality. — Chiriqui. Friese's specimens of vogti 

 are in his private collection. 



Mostly black, but the disc of the thorax usually mostly covered with 

 dark cinereous pile and the apical dorsal abdotninal segments clothed 

 with white hair. Ocelli of queen and worker placed almost exactly in 

 the narrowest part of the vertex. Legs black. Wings very dark 



Queen. Head. — Rather broad and rounded. Pile all dark. Malar 

 space shorter than its width at apex, but little more than one-sixth as 

 long as the eye. Clypeus very delicately punctate and shining. 

 Ocelli large and placed considerably below the supra-orbital line, just 



TRANS. AM. ENT. SOC, XXXIX. 



