506 PROCEEDINGS OF THE NATIONAL MUSETJM vol. iii 



Legs: Postero ventral margin of liind tibia with fine tubercles basal 

 of distinct angulation at basal sixth (fig. 155) and three or four sub- 

 apical spines. 



Sternites: Without distinct punctures except in spiracular area. 



Terminalia: Genital capsule laterally impressed and more distinctly 

 punctate, apical margin slightlj^ elevated either side of broad, deep, 

 U-shaped median emargination (fig. 177); gonostylus as illustrated 

 (fig. 235). 



Length of body: 8.53(7.34-9.73). 



Female: Similar to male but posterior tibia without subbasal 

 angulation and with five or sLx subapical spines on posteroventral 

 margin. 



Head: Length-width ratio, 1.28(1.13-1 .56) : 1.93(1.67-2.27); inter- 

 ocular width, 1.10(1.03-1.24). Antennal segments: I, 0.36(0.28-0.43); 

 II, 0.36(0.28-0.43); III, 0.52(0.50-0.58); IV, 0.62(0.53-0.76); V, 

 0.68(0.63-0.80). Labial segments: I, 0.64(0.60-0.80); II, 1.09(1.00- 

 1.23); III, 0.83(0.71-0.93); IV, 0.51(0.46-0.58). 



Pronotum: Length-width ratio, 2.31(2.02-2.86) :4.29(3. 91-5.06). 



Scutellum: Length-width ratio, 2.64(2.40-3.20) :2. 60(2.28-3.20). 



Length of body: 7.91(7.01-9.45). 



Type data. — Fabricius' type (Copen) was from "Cajenne" in 

 French Guiana. The type (OxUniv) of Cydnus serripes was described 

 by Westwood from "Insula Sti. Vincentii"; Dallas' type of Aethus 

 margo, a male (BrM) without posterior tibiae, was reported from 

 "Columbia [!]." Since Signoret proposed the name confusus for those 

 Mexican specimens reported by StM (1862, p. 95) as margo, those 

 specimens must constitute the type series and probably are now in 

 the StM collection in the Naturhistoriska Riksmuscum, Stockholm. 



Specimens studied. — 43 males, 67 females. 



Mexico: Chiapas: Finca Esperanza, La Esperanza; May. Guerrero: Iquala; 

 September. Mexico: Tejupilco: September. San Luis Potosi: El Salto, Tamazun- 

 chale, Valles; May, June. Yucutdn: Colonia Yucutdn; August. 



Guatemala: Finca El Cipres, south of Flores, Sacapulas; June. 



Panama: Progreso. Canal Zone: Madden Dam. 



Honduras. "Ratuch River"; June. 



Nicaragua; Managua. 



Grenada: Balthazar (windward side), Grand Etang (leeward side). 



Trinidad: Near Port of Spain, St. Augustine; August. 



French Guiana: Cayenne; February. 



British Guiana: Source of Rfo Essequibo. 



Venezuela: M^rida, Caracas. 



Colombia- "W. Colomb.," Bonda, Call, Muzo, Santa Marta; May, November. 



Ecuador: Balzapamba; March. 



Brazil: Grajaii, Mandos, Matto Grosso, Mirim, Pard, Pernambuco, Rio de 

 Janeiro, Santa Cruz, Santar^m, Sao Paulo, Taperina; July to October. 



Peru: Yurimaguas; April, June. 



Paraguay: Horqueta, Sapucay; February, July. 



