Malloch — The Generic Status of Chrysanthrax Osten Sacken. 69 



Hyalanthrax alternata Say. 



Anthrax alternata Say, Jour. Acad. Nat. Sci. Phil., Vol. 3, 1823, p. 45. 

 Anthrax consanguinea Macquart, Dipt. Exot., Vol. 2, Pt. 1, 1841, p. 69. 

 Anthrax scrobicidata Loew, Berl. Ent. Zeitschr., 1869, p. 24. 

 Anthrax stenozona Loew, Berl. Ent. Zeitschr., 1869, p. 25. 

 Hyalanthrax stenozona? Osten Sacken, Biol. Cent. Amer., Vol. 1, 1886, 

 p. 138. 



Length, 15 mm. Whitish testaceous, slightly shining, cephalic and 

 abdominal thorns dark brown. Upper pair of cephalic processes very 

 stout, contiguous for the greater portion of their length, their apices 

 flattened and truncate (Fig. 7); lateral processes much larger than in 

 lateralis and more slender than in hypomelas (Figs. 9, 10, 11); distance 

 from base of ventral thorns on lower margin of face to apex of first sec- 

 tion of sheath of mouth parts less than twice the length of the apical 

 part of the latter (Fig. 4), the corresponding distance in lateralis and 

 hypomelas differing from that in alternata as shown in figures 5 and 6. 

 In the armature of the abdomen alternata differs from hypomelas and 

 lateralis in the complete transverse median series of hairs on the eighth 

 ventral segment, these hairs being absent in hypomelas, and lateralis 

 having but two on each side. Lateral view of apical abdominal segment 

 as in figure 8. 



I have before me two pupae of alternata, one received from J. J. Davis 

 and the other from J. A. Hyslop, both of the U. S. Bureau of Ento- 

 mology. The example sent by Davis is that of a specimen reared from a 

 lepidopterous pupa ; the one from Hyslop is that referred to by him in a 

 recent paper* on the life history of Meracantha contracta, in the larvae 

 of which the species is parasitic. 



The three species of this group that I have examined are very closely 

 allied and are readily distinguished from other Bombyliidae known to me 

 by the stout upper cephalic processes, which are closely contiguous at 

 base, and by the very small size of the lateral cephalic processes and 

 their close approximation to the central line of the head, their bases 

 being but little farther from that line than are those of the upper pair. 



• Psyche, Vol. 22, 1915, p. 41. 



