GROUP ALTERNATA 



Alternata is the sole species placed in the group. It is distin- 

 guished by the large sized, square cut primaries; the orbicular large, 

 usually elongate and oblique ; the reniform large and broad, with a 

 tendency to constrict in the center. Both spots are clearly outlined 

 and margined by a whitish clear-cut line. Terminal area usually 

 lighter than the ground, which may be any color from tan to gray. 

 The s.t. line is peculiar to the species, having two large "teeth" 

 with an indented area between and the last tooth subdivided into a 

 W-mark (similar to the W-mark of Smith in Hadena and Mamestra, 

 and Hampson in Trachea and Polia). Thorax smooth, without sign 

 of a crest. Antennae ciliated, with longer setae on each joint. The 

 ampulla of the clasper is small and membraneous. There is very 

 little variation in the genitalia. 



Alternata appears to be a widely distributed, common species, 

 in a very stable evolutionary state. 



LAMPRA ALTERNATA, Grt. 



1864. Grt., Proc. Ent. Soc. Phil., Ill, 526, pi. 5, f. 8, Noctua. 



1869. Grt, Trans. Am. Ent. Soc, II, 309, Agrotis. 



1874. Grt., Can. Ent., VI, 15, Cerastis. 



1874. Grt., Can. Ent, VI, 214, Agrotis. 



1878. Grt., Can. Ent., X, 235, Agrotis. 



1883. Grt., Proc^ Am. Phil. Soc.,' XXI, 155,=cupida var., (Agrotis). 



1889. Butler, Trans. Ent. Soc. Lend., 382,=j)hyUo2)liora, (Amathes). 



1890. Sm., BuU. U. S. N. M., XXXVIII, 23, Rlujncliagrotis. 

 1893. Sm., ]3ull. U. S. N. M., XLIV, 53, Rliijnclwgrotis. 



1895. Grt., Abb. Nat. Ver., Bremen, XIV, 18, Agrotis (Lampra). 



1903. Hamp., Cat. Lep. Phal. B. M., IV, 637, pi. LXXVII, f. 12, Triphaena. 



1903. Holl., Moth Book, p. 178, pi. XXI, f. 20, Rhynchagrotis. 



1908. Sm., Can. Ent., XP, 286, Rhynchagrotis. 



NOCTUA ALTERNATA, nov. .sp. (Plate 5, fig. 8 ? ) 



Anterior wings pale dull ochraceous, slightly olivaceous, subterminal 

 space brownish, with a purplish lustre; terminal space very pale ochraceous, 

 ordinary lines geminate, distinct, brownish. Basal, sub-basal and median 

 spaces uniform dull dark ochraceous, slightly paler at extreme base and 

 toward the costa; median space partially shaded with a purplish lustre. 

 Basal half-line geminate, distinct, brownish; transverse anterior oblique, 

 geminate, with a simple subcostal dentation, thence undulate to internal 

 margin. Ordinary sjjots very distinct, surrounded by paler annuli, with 

 brownish centers, the reniform slightly shaded with ferruginous; trans- 

 verse posterior line geminate, interrupted, nearly straight, but little arc- 

 uated at the disc, followed by minute black dots on the veins, wliich latter 

 are paler in the subterminal space. Subterminal space dark brownish, witli 

 a purplish luster, distinctly relieved from the terminal space by the sub- 

 terminal darker marginal line, which is lost inwardly, owing to the dark 

 color of the subterminal space. Terminal space paler than the median 

 and basal spaces, with a series of terminal blackisli dots between tlie veins, 

 fringes darlv. Posterior wings uniform blackish cinereous, hardly darker 

 shaded along external margin, immacvUate; fringes paler with a blackish 

 central line. Head and prothorax rather bright ochraceous; tegulae and 

 thorax concolorous with anterior wings; abdomen cinereous above, witli 

 reddish anal tuft and sliaded witii the same color beneath. Under surface 

 of anterior wings reddish along the costa and external margin, rest of the 



