ART. 9 AMERICAN XYLOTTNE SYRPIIID-FLIES SHANNON 21 



XYLOTOMIMA BATON (Walker) 



Xylota batmi Walker, List 3, 1849, p. 554. 



Xylota fraudulosa Loew, (Museum of Comparative Zoology). 



For many years this species has been standing as a synonym of 

 ejuncida Say. An examination of the type shows that the metaster- 

 num is pilose (pubescent in ejuncida) and other characters show it 

 to be conspecific with fraudulosa. 



One of our most common species in eastern North America. Ap- 

 parently this species is very closely related to the European nemorum 

 Fabricius, differing chiefly in the more yellowish antennae and 

 yellow base of arista. 



A small rather robust species, 8-9 mm. 



Male. — Frontal triangle silvery pollinose; arista yellowish at base. 

 darker beyond, shorter than width of face; femora black except 

 extreme apices; hind tibia black except base; hind tarsi black dor- 

 sally, yellowish ventrally; second and third tergites with quadrate 

 spots; postthoracic sj)iracle smaller than third antennal joint. 



Female. — Front fairly broad, arista a little more than twice width 

 of front across ocelli; abdominal spots small, sometimes obsolete. 



Distribution. — Has been reported (under the name fraudulosa) 

 from nearly all parts of the United States except Arizona. The 

 western records probably should be applied to nemorum americana. 



Type. — In British Museum. 



XYLOTOMIMA NEMORUM (Fabricius) 

 Xylota dascon Walker. ( In Bi-itisli Museum ) . 



It is uncertain whether typical nemorum occurs in America. Until 

 this can be ascertained the writer proposes calling our closest allied 

 form a variety of nemor-uin. The specimen described by Walker 

 as dascon appears to be a synonym of neimoruin. Country unknown. 



Type. — Location unknown. 



XYLOTOMIMA NEMORUM AMERICANA, new variety 



This form differs from baton b}'^ having the arista dark brown 

 throughout or yellowish brown at base and gradually merging into 

 darker color beyond; and in the male the basal lobe of the stylo is 

 smaller. 



The two forms are very closely allied but according to the ma- 

 terial at hand baton is a species of the Eastern United States while 

 nemomm americana is of western distribution. The latter differs 

 from European nemoi^urm chiefly in having the mesonotal i)ile black 

 whereas it is pale in typical nemorum. 



