492 PROCEEDINGS OF THE NATIONAL MUSEUM vol. iis 



stocky. Legs may have dark brown to black infuscation on all femora 

 and tibiae or may be all yellowish brown ; most often some infuscation 

 medially on hindfemora and tibiae; all coxae black or deep reddish 

 brown. Wing veins yellow to yellowish brown; marginal linear to 

 about twice the width of postmarginal; marginal averages .36 mm. 

 (.30-.42) and postmarginal averages .28 mm. (.22-.37) in length; 

 thus marginal is always longer than postmarginal; stigmal club small 

 and more or less rectangular in shape. 



Males: Black. Length averages 3.4 mm. (3.0-4.0). Scape of 

 antenna most often black; less often base of scape with varying 

 amounts of yellow or yellowish brown. Legs variable; may be black 

 to dark-brown infuscation on all femora and tibiae; less often infusca- 

 tion on hindfemora only or legs all yellowish brown. Wing veins 

 brown to brownish yellow; marginal vein averages .33 mm. (.27-.37) 

 and postmarginal averages .24 mm. (.20-.27) in length. 



Types: Lectotype female and allotype male, USNM 25503, Agri- 

 culture rearing number 113205. One additional female with Agri- 

 culture number 11320^ in the U.S. National Museum collection, 

 Washington, D.C. The &st female cited above is labelled and desig- 

 nated as lectotype. Additional specimens used in connection with the 

 redescription include 89 females and 29 males also in the U.S. National 

 Museum collection. 



Type locality: Rosslyn, Va., F. H. Chittenden. 



Host: From the larva of Tyloderma foveolatum Say. 



Distribution: Canada and the eastern two-thirds of the United 

 States, Ontario, south to South Carolina and Louisiana and west to 

 Texas and Arizona. 



Remarks: In 1896 Ashmead described Eurytoma tylodermatis as a 

 parasite of the "larva of a beetle, Tyloderma foveolatum Say." Addi- 

 tional determinations during the succeeding j^^ears have raised the 

 number of hosts of E. tylodermatis to 56 or more (Peck, 1951, in 

 Muesebeck et al., U.S. Dept. Agric. Monogr., no. 2). 



This is due in part to Ashmead's description which is so general that 

 it encompasses many species of the genus Eurytoma. Furthermore, 

 his description was based on two females and one male specimen only, 

 which was not enough material to give an adequate picture of the 

 range and limits of variation of the species. 



In 1951 the U.S. National Museum loaned me all the specimens 

 which had been accumulating in their collection of Hymenoptera for 

 many years under the label of E. tylodermatis. A study was made of 

 the material plus specimens in my own collection amounting alto- 

 gether to about 4000 individuals. Even this number was not enough 

 to give an adequate picture of the geographical distribution, or the 

 range of variation of the several species in the complex. Many 



