230 PROCEEDINGS OF THE NATIONAL MUSEUM vol. ii4 



Aclerls semiannula (Robinson), new combination 



Teras semiannula. — Robinson, 1869, Trans. Amer. Ent, Soc, vol. 2, p. 282, pi. 



7, fig. 70.— Zeller, 1875, Verhandl. zool.-bot. Ges. Wien, vol. 25, p. 212. 

 Teras ferrugana var. semiannula. — Walsingham, 1879, Illustrations of typical 



specimens of Lepidoptera Heterocera, pt. 4, p. 76. 

 Teras ferrugana. — Fernald, 1882, Trans. Amer. Ent. Soc, vol. 10, p. 8 (in part). 

 Alceris [sic] ferrugana. — Fernald, [1903], U.S. Nat. Mus. Bull. 52, p. 474, no. 



5316 (in part), 1902. 

 Peronea ferrugana (in part). — Meyrick, 1912, in Wagner, Lepidopterorum cata- 



logus, pt. 10, p. 60; 1913, in Wytsman, Genera insectorum, fasc. 149, p. 62. — 



Barnes and McDunnough, 1917, Check list of the Lepidoptera of Boreal 



America, p. 178, no. 7413. 

 Peronea stadiana Barnes and Busck, 1920, Contr. Nat. Hist. Lep. North America, 



vol. 4, p. 217. 

 Peronea ferrugana form semiannula. — Forbes, [1924], Cornell Univ. Agr. Exp. 



Stat. Mem. 68, p. 487, 1923. 

 Peronea semiannula. — McDunnough, 1934, Canadian Journ. Res., vol. 11, pp. 322, 



328 (fig. 8), 332 (fig. 9); 1935, Canadian Ent., vol. 67, p. 148; 1939, Mem. 



Southern California Acad. Sci., vol. 2, p. 59, no. 7514. 



Types. — Holotype of semiannula, female, Pennsylvania, in the 

 Academy of Natm^al Sciences of Philadelphia. Holotype of stadiana, 

 male, Ottawa, Ontario, Sept. 18, 1905 (C. H. Yomig), USNM. 



Remarks. — -As one of the characters of this species, McDunnough 

 (1934) mentioned the presence of a pair of apical cornuti and of two 

 more cornuti with a chitinous plate between them in the central 

 part of vesica. In most of the examined specimens of semiannula, 

 the present author observed the same, although the position of the 

 plate was not always as above, but was sometimes at one side of two 

 central cornuti. In one male specimen from Montclair, N.J. (Nov. 2, 

 1903, W. D. Kearfott; genitalia on slide 224-Obr.; AMNH), 

 only one cornutus of the central group is present, but the remainmg 

 armature of the vesica is normal. There is a male specimen from 

 New York (Big Indian Valley, Catskill Mountains, July 10, 1906, 

 R. F. Pearsall; genitalia on slide 234-Obr. ; AMNH) in which the num- 

 ber of cornuti is normal, but one cornutus in the central group is thin- 

 ner and somewhat shorter than the other. This specimen has broad 

 brownish -ochreous fore wings, much more intensively colored than 

 usual in semiannula. The markings of the fore wings are also some- 

 what different, and there are some doubts about the systematic 

 position of this specimen. Two males and two females from Essex 

 County, N.J. (May, W. D. Kearfott; genitaha on slides 222-Obr., 

 223-Obr., and 231-Obr.; AMNH), reared from Betula alba, have 

 forewings colored similarly to those of the specimen from New York. 

 The forewings are shorter and relatively broader than in the common 

 form of semiannula, but the genitalia do not differ in any way from 

 those of this species. Should it be confirmed that the food plant of 



