lv)2i'] The North American Species of Cryptolucilia. 91 



2. Cryptolucilia cornicina (Fabricius) (=Musca cornicina 

 Fabricius, Spec. Insect., 2, 1871, p. 438). Thorax without 

 acrosticals before the transverse suture; four posterior dorso- 

 centrals. Front comparatively narrower in both sexes. 



This species is thus far unknown from North America. 

 In Europe, however, it is not less common than the foregoing. 

 I have examined a male from Rambouillct, France, kindly sent 

 to me by Dr. Villeneuvc. 



Stein (Arch. f. Naturg., 83, Abt. A, Heft 1, 1919, p. 105) 

 synonymizes Pyrellia frontalis Thomson (Eugenies Resa, 2, 

 Zool., 1, Diptera, 1868, p. 545), from Cahfornia, with C. cornicina. 

 Whether this is based on an examination of Thomson's tjqoe 

 specimen is not known, but the description appHes equally well 

 to C ccesarion. 



The failure of North American entomologists to separate 

 c(vsarion and cornicina is evidently due to the confusion on this 

 subject which has been allowed to prevail until recent years 

 by European dipterists. Even Girschner while establishing his 

 genus Pseudopyr cilia on "P. coi-nicia Fll." was evidently using 

 specimens of ccesarion, since he expressly mentions among the 

 generic characters the presence of a pair of heavy acrosticals. 

 Schnabl and Dziedzicki (Die Anthomyiden. Nov. Acta Ac. 

 Leop. Car. Nat. Cur., 95, 1911, pp. 224 and 229) repeated the 

 same error. The two species, however, have been correctly 

 separated by Stein (Arch. f. Naturg., 81, Abt. A, Heft 10, 1916, 

 p. 18), who has also examined their type specimens. 



Considering the constant association of Cryptolucilia 

 ccesarion with cattle dung, the question might be raised whether 

 this fly has not been imported from the Old World through the 

 agency of man, at a comparatively recent date. It is, moreover, 

 remarkable that of the two common Palearctic species, only 

 one has thus far established itself in North America. 



