﻿496 PROCEEDINGS OF THE NATIONAL MUSEUM tol. 102 



exocorium. Small black spots below abdominal setigerous punctures 

 with greatest diameter not more than one-twelfth length of supporting 

 segment. 



Form narrowly elongate. Jugae loosely contiguous along entire 

 inner margin before tylus, slightly deflected inwardly. Protonum 

 with transverse constriction hardly noticeable; lateral margins slightly 

 concave before the humeral angles, edge almost carinate. 



Length: Males, 9-10 mm.; females, 8.6-11.8 mm. 



Width of humeral angles: Males, 2.25-2.45 mm.; females, 2.3-2.8 

 mm. 



Antennae of male (holotype specimen) : Relative length of segments, 

 40:85:90:80:63. First three segments as shown on plate 48, figure 43. 



Antennae of female (allotype specimen): Relative length of segments, 

 40 :115 :55 :70 :60. First three segments as shown on plate 48, figure 44. 



Male genitalia: Hypopygium, clasper, penial vesiculae, and penial 

 plates as shown on plate 48, figures 55, 56, and plate 47, figures 16, 

 17, and 18. 



Variation. — If this species is properly interpreted it exhibits a 

 remarkable degree of variation. This variation involves size, color, 

 and relative lengths of the antennal segments. Among the specimens 

 studied those from Chaco and C6rdoba are largest and darkest, and 

 the males generally have the third segment of the antennae longer 

 than the second. A series of 18 specimens from Conhello, La Pampa, 

 are consistently smaller, paler, and several males have the third anten- 

 nal segment shorter than the second. Variation in relative length 

 of the antennal segments is even more pronounced among female 

 specimens. (See plate 48, figures 43 and 44.) The ratio of lengths 

 of the second to the third segments of the allotype from Agua de Oro, 

 C6rdoba, is 115:50, of a female from Mendoza, 110:75, and another 

 from La Rioja is 100:60. The black spots below the abdominal 

 setigerous punctures are reduced in many specimens and often absent. 



These differences are as great as those existing between certain 

 species of Mecidea ; however, the degree of intergradation found among 

 the specimens studied, together with the relative stability of the male 

 genital structures, are accepted as an indication that only one species 

 is involved. 



Types. — Holotype, male, Tucum§,n, Argentina, February 26, 1946, 

 P. A. Berry (U.S.N.M. No. 58422). Allotype, Agua de Oro, C6rdoba, 

 Argentina (M.A.C.N.). 



Para types: ARGENTINA: Tucuman: Tucuman, 1 cf , February 

 26, 1946, P. A. Berry (U.S.N.M.); 1 9, April 1932; 4 cf , 2 9, Novem- 

 ber and December 1944, R. Golback; 1 cf , December 1946, T. Araoz; 

 1 9, October and November 1949, R. Golback. Los Puestos, IcT, 

 April 20, 1948, R. Golback. Parque Aconguija, 1 cf , April 7, 1947, 



