CYDNIDAE OF THE WESTERN HEMISPHERE — FROESCHNER 477 



Steriiites: Shining, impunctate except in spiracular area. 



Terminalia: Genital capsule distinctly punctate except for broad 

 middle line, apical margin broadly, shallowl}^ emarginate medially; 

 gonostylus as illustrated (fig. 223). 



Length of body: 7.83(7.50-8.25). 



Female: Similar to male, but without modification of posterior 

 tibia. 



Head: Length-width ratio, 1.24(1.20-1.30) :L87(L78-L98); inter- 

 ocular width, 1.25(1.20-1.30). Antennal segments: I, 0.37(0.32-0.40) ; 

 II, 0.49(0.43-0.60); III, 0.53(0.46-0.60); IV, 0.69(0.60-0.80); V, 

 0.74(0.70-0.80). Labial segments: I, 0.53(0.50-0.56); II, 1.03(0.96- 

 1.18); III, 0.82(0.76-0.93); IV, 0.53(0.50-0.57). 



Pronotum: Length-width ratio, 2.23(2.08-2.42) :4.07 (3.76-4.43). 



Scutellum: Length-width ratio, 2.77(2.61-2.97) :2.44(2.34-2.66). 



Length of body: 7.74(7.20-8.52). 



Type data. — Holotype male and allotype female (both CalAc), 5 

 miles north of Tizayuca, Hidalgo, Mexico, Nov. 13, 1946, E. S. Ross. 

 Paratypes as follows : 



Mexico: Hidalgo: Same data as types, 5 males, 8 females (CalAc, USNM, 

 RCF). "Guerrero Mills," W. M. Mann, 1 male, 1 female (MCZ). Distrito 

 Federal: "15 mi. S. of El Guarda," Nov. 14, 1946, E. S. Ross, 1 male, 2 females 

 (CalAc); July 10, 1 female (Mex). Pen6n del Marquis, March 27, Wheeler, 1 

 male, 4 females (MCZ). Pedregal, June 29, 1932, 1 female (RLU). Lomas de 

 Chapultepec, July 14, 1932, 1 female (RLU). Pen6n, Viejo, June 21, 1932, 1 

 female (RLU). Pedregal San Angel, Aug. 27, 1939, C. Bolivar, 1 female (Pel). 

 State unknown: MinatitMn, Feb. 1, 1892, H. Osborn, 1 male labeled Pancjaeus 

 rugifrons H-S., Pangaeus confusus Sign., and Pangaeus discrepans Uhl. (USNM). 



United States: Texas: Devil's River, June 6, 1907, Bishop and Pratt, at light, 

 1 female (USNM). Colorado City, July 17, 1927, L. A. Stephenson, 1 female 

 (KU). 



Discussion. — This form is discussed with the preceding species. 

 Subgenus Pangaeus {Pangaeus) Stal 



Pangaeus Stai, 1862, p. 95. 



Diagnosis. — The key character concerning the extensiveness of 

 the mesopleural evaporatorium is the most reliable feature for 

 separating this subgenus from subgenus Homalopoi-us. 



Description. — The generic description as modified by the notes in 

 the generic discussion will furnish sufficient description for this 

 subgenus. 



Type of subgenus. — Aethus margo Dallas, subsequent designation 

 by Van Duzee (1914, p. 378); this name is a synonym of Cydnus 

 aethiops Fabricius, which is treated in the present paper as a member 

 of the genus Pangaeus. For explanation of this synonymy see the 

 discussion under Pangaeus aethiops. 



