318 THE CANADIAN ENTOMOLOGIST. 



ON CEA I MM AC UL A AND ALLIED SPECIES. 



BY WM. BARNES, M.D., AND J. MCDUNNOUGH, PH.D., DECATUR, ILL. 



In sorting over material from Arizona and the southwest we have 

 come across four species very similar in outward appearance, but struc- 

 turally widely different. Two of the species are fairly well known, but the 

 other two are apparently undescribed. 



The first species before us is 'unmaciila Grt.; (not immaciilata as 

 given in Dyar's List), the type of the genus Cea. The species was 

 originally described from Arizona, but our series of some twenty speci- 

 mens all come from Deming, N. Mex. It may be recognized by its 

 immaculate creamy-white primaries, which in very few cases show faint 

 traces of t. a. and t. p. lines and reniform. The legs are unarmed, with 

 neither spines nor claws ; the front possesses a fairly prominent rounded 

 protuberance with a distinct corneous infra-clypeal plate. According to 

 Hampson (Cat. Lep. Phal., IX, 280), who, however, does not know the 

 species personally, the protuberance is bare of scales ; this, however, does 

 not apply ; with the exception of a small black point in the centre of the 

 same, it is thickly covered with closely-appressed scales, of a slightly 

 darker ochreous tint than that of the surrounding area. 



The second species under consideration is hixa Grt., described from 

 specimens taken by Prof. Snow in N. Mexico, and made by Grote the 

 type of a new genus, Bessiila. In Dyar's Catalogue this species is placed 

 close to immacula, but Hampson separates it very widely, placing 

 it at the very beginning of the Noctuidce in his subfamily Agrotince, 

 characterized by spined tibiae of middle and hind legs; luxa is placed in the 

 genus Schijiia Hbn., of which Bessula is made a synonym. Besides 

 spined middle and hind tibiae, luxa possesses on the fore tibiae a strong 

 curved claw on the inner side, preceded by two minute spines, which 

 often appear wanting, owing probably to breakage ; further, on the outer 

 side of the tibiae, is a row of three claw-like spines, the largest being at 

 the extremity of the joint. The front is rounded, scarcely as full as in 

 immacttla, with appressed scales without the central black point, and the 

 infra-clypeal plate is present. In general appearance luxa is yellower 

 than immacula, and may at once be distinguished by the light-brown 

 dotted t. p. line, the cellular dots and the dots at the base of the fringes. 

 As in many cases these show a tendency to obsolescence, structural 

 characters are of great value in separating the species. The sixteen speci- 

 mens before us are from So. Arizona. 



September, 1911 



