198 Proceedings of the Biological Society of Washington. 



long, the pile on the mesonotum in part luteous and the squamae 

 whitish. 



Specimens of this species were sent to the late Mr. Coquillett at the 

 National Museum by Mr. C. T. Greene for determination. Coquillett 

 gave it only the manuscript name Chilosia similis which was published 

 in the last edition of the List of New Jersey Insects, 1909. This name is 

 retained for the species. 



Its late occurrence in the year, September and October, along with 

 occasional specimens of C. pallipes, is a characteristic worth noting, as in 

 the eastern United States most of the species occur in the spring. 



Note on Myiolepta. 



Xylota tuberans was described by Williston in his Synopsis of the 

 Syrphidge * from a single male specimen from Texas. He states that the 

 species can not properly be placed in the genus Xylota, as it differs in the 

 position of the discal cross vein, the profile of the face, etc. A careful 

 comparison of this specimen with species of the genus Myiolepta shows 

 that it belongs to this genus, and, moreover, is conspecific with M. nigra 

 Loew. It is curious that Williston, after noting the essential characters, 

 failed to recognize his Xylota tuberans as a true Myiolepta. 



In Myiolepta the discal cross-vein is placed before the middle of the 

 discal cell and is rectangular; the first posterior cell is closed at the 

 margin of the wing and the second vein turns abruptly upwards near its 

 tip. The male has a tuberculate face and short, rather thick pile on the 

 Irons. All the femora are somewhat swollen at least and spinose teneath. 

 M. bella differs in having the frons bare in the male, the second vein 

 turned upwards less abruptly and a sawtooth like projection on the hind 

 femora below. 



In Xylota the cross-vein joins the discal cell beyond the middle and is 

 oblique, the first posterior cell is closed some distance before the wing 

 margin and the second vein turns upwards less obliquely. The frons in 

 the males is bare, except in some species (chalybea, for example) there 

 is very fine pale pile along the eyes. The face has no trace of a tubercle 

 in either sex and the femora of the front and middle legs are not swollen 

 nor spinose beneath. 



Xylota tuberans possesses the characteristics noted under the genus 

 Myiolepta. Comparison of the type with Williston's description of M. 

 nigra female, and Hine's description t of M. nigra male, and a male 

 specimen collected in this vicinity by Mr. Knab, proves it to be this 

 species. Other characters which may be noted for the species are as 

 follows : The costa at the base is white with whitish vestiture, the origin 

 of the second and third veins bears very small, black bristles which con- 

 tinue for a short distance along the third vein ; middle and hind legs 

 have the first three tarsal joints whitish. 



The genus Myiolepta has a closer relationship with Tropidia than with 



• Bull. 30, U. S. N. M., pp. 225-226. 1886. 

 t Ohio Nat. XIV, p. 207, 1913. 



