AKT. 16 NORTH AMERICAN ICHNEUMON-FLIES CUSHMAN 19 



Three females, the type captured August 28, 1909, by W. S. Fisher ; 

 one from New York; and one from Riley County, Kans., November, 

 Marlatt. 



LISTKOGNATHUS ALBOMACULATUS variety NUBILIPENNIS (CrcMon) 



Mcsostenus nubilipentiis Ceesson, Can. Ent., vol. 10, 1878, p. 205. Type. — No. 

 1184, Acad. Nat. Sci. Phila. 



Discussion based on type. 



Differs from typical form in having the hind coxae largely red 

 and in having a distinct, though not deeply infumate, cloud in the 

 front wing, 



Cresson says " f rons unarmed ", but the structure of the frons is 

 the same as in specimens with the horn. There is great variation 

 in the size of the horn, and the reduction in size is apparently 

 carried to the extreme in this specimen. 



A male from Vienna, Va., April 22, 1915 (R. A. Cushman), which 

 I have somewhat doubtfully determined as this variety has a dis- 

 tinct frontal horn, lacks the alar cloud, and has the hind coxae red 

 and only slightly paler above. 



The type is from Georgia. 



LISTKOGNATHUS ALBOMACULATUS variety SAGAX (Provancher) 



Mesostenus sagax Provancheb, Nat. Can., vol. 11, 1879, p. 112, fig. 2e, female; 

 Faune Ent. Can. Hym., 1883, p. 345, fig. 35e, female. Ti/pe.— Public 

 Museum, Quebec. 



Discussion based on notes by S. A. Rohwer on type and three 

 females and one male in the National collection determined by the 

 writer. 



According to Rohwer's notes the type will run in Ashmead's key 

 to Mesostenoideus, which would indicate that the frons is unarmed, 

 but one of the females in the National collection agrees so nearly 

 perfectly with Provancher's description and with the additional 

 characters in Rohwer's notes that the determination appears correct. 



So identified this form is probably nothing but a more or less 

 melanic variation of the species hardly worthy of varietal rank. 



In its extreme form as represented by the type the head is entirely 

 without white markings; on the thorax only the scutejlum and 

 apophyses are white marked; and the coxae are entirely black. 



In the National Museum specimen that approaches closest to the 

 type in coloration the frontal orbits are narrowly white; there are 

 small white spots on dorsal margin of pronotum, base of tegula, 

 subalar tubercle, and upper side of middle coxa. In the most higlily 

 ornamented specimen these markings are larger, the orbital mark 

 extends to the sides of the face, and there are additional white 

 markings on cheeks, clypeus, mandibles, lower corner of pronotum. 



