j»HT. 5 GENERIC REVISION OF THE FOSSORIAL WASPS PARKER 169 



BICYRTES VENTRALIS (Say) 



Figure 16 



Monedula ventralis Say, Exp. St. Peters River, vol. 2, 1824, p. 336. 



Bicyrtes servilil Leh^eletier, Hist. Nat., vol. 3, 1845, p. 63. 



BemHdula ventralis Handlirsch, Sitz. Akud. Wissensch. Wien, Math.-Nat. CI., 



vol. 98, 1889, p. 495.— Daxla Torre, Cat. Ilym., vol. 8, 1897, p. 490. 

 Bicyrtes ventralis Pabkek, Proc. U. S. Nat. Mu?., vol. 52, 1917, p. 62. 



This is the most abundant species of the genus in North America 

 ;and is widely distributed over the United States and Canada. In the 

 western part of the United States it is largely replaced by parata. 

 The males of these two species are the only ones that have the middle 

 femur provided with a distinct tooth near the proximal end below. 

 Along with the wide dispersal of ventralis goes a wide variation in 

 the extent and color of the maculations, and this variation holds 

 true for both males and females. The color varies from orange 

 jellow through lighter shades to light creamy white. My observa- 

 tions on this species seem to indicate that in the western part of its 

 range it appears only in the light-colored forms. The wings are 

 infumated, but the degree of infumation a|so varies. 



BICYRTES PARATA (Provancher) 



Monedulu parata Pbovanchek, Add. Hym. Quebec, 1888, p. 416. 

 Beiiibidula parata Fox, Proc. Acad. Sci. Phila., 1895, p. 353. 

 Bembidula meliloti Rohwer, Ent. News, vol. 19, 1908, p. 376. 

 Bicyrtes parata Pabkeb, Proc. U. S. Nat. Mus., vol. 52, 1917, p. 64. 



This is a western species and as now recognized appears under 

 two forms, one in which both males and females have the maculationg 

 yellow and the other in which both males and females have the 

 maculations white. As was pointed out in the notes on venfraUs, 

 that species and this one, in regard to the male, are characterized by 

 the presence of a tooth on the middle femur. Furthermore, the 

 antennae of the males of these two species have the same modifica- 

 tions. The male genitalia of the two species show no trustworthy 

 differences. Even the infumation of the wings can not be rejied upon 

 to separate the two species. It follows, therefore, that we must 

 depend upon the maculations, upon their extent and their color, 

 for characters with which to separate the two species. 



On typical forms of parata the color of the maculations is yellow, 

 the fasciae on the tergites are broad, either all narrowly interrupted or 

 some interrupted and some continuous. In addition, the sixth tergite 

 of the female and the seventh of the male bear conspicuous lateral spots- 

 In typical forms of ventraJls the fasciae on the tergites are always 

 interrupted, relatively narrow, and the fascia on the first tergite is 

 much reduced or wanting. The sixth termite of the female and the 



