306 Professor Williston on the 



together. Mesonotum shining, dark pitchy, a little more yellowish 

 on each side in front; on the posterior part subopaque ; sides 

 lightly pollinose. Pleurae brown and yellowish, light yellow 

 pollinose. Abdomen black or brown, the posterior margin of each 

 segment whitish, the hind angles reddish. Coxae light yellow ; 

 femora black or brown, with the base and a preapical ring red or 

 yellow ; anterior tibiae yellowish, with the distal part yellow ; 

 hind tibiae black or deep brown, with the proximal part yellow ; 

 anterior tarsi yellow ; hind tarsi black. Wings pure hyaline, with 

 the tip blackish. Empodium about half the length of the claws. 

 Occiput without bristles. 



Two specimens. In one the colours throughout are 

 not so deep, and the tip of the wing is cinereous. 



HOLCOCEPHALA. 



Jaennicke, Abhandl. Senckenb. Gesellsch, vi., 1867. 



Two male specimens of a species related to H. calva, 

 Loew, but with the legs nearly black, and the abdomen 

 not clavate. 



BOMBYLIIDJE. 



Geron. 



Meigen, Syst. Beschr., ii., 223, 1 820. 



1. Geron senilis. (PL XI., fig. 81, antenna.) 



Geron senilis, Fabricius, Ent. Syst., iv., 411; Syst. 

 Antl., 135, Bomhylius ] Wiedemann, Auss. Zw. 

 Ins., i., 357 ; Macquart, Dipt. Exot., Suppl., i., 119. 



Hah. West Indies ; Texas. 



One male specimen, agreeing very well with Wiede- 

 mann's description. 



THEREYID.^. 



PSILOCEPHALA. 



Zetterstedt, Ins. Lapp., 525, 1840. 



1. Psilocephala argentata. (PI. XI., fig. 82, antenna.) 



? Thereva argentata, Bellardi, Saggio, ii., 90 ; Roeder, 

 Stett. Ent. Zeit., 1885, 340.— Mexico, Porto Rico. 



(^. Black ; abdomen silvery white, except a large spot on the 

 anterior ancles. Length 6-8 mm. 



