PTYCHODERES., 303 
(1855), and depressus, Jek. (1855). Two of these forms are confined to Central America 
(dtvittatus and rugicollis), while one (mixtus) ranges from Southern Brazil northward to 
Nicaragua. 
Key to the Central-American Species. 
Pronotum with a clayish-white vittaon each side . . . .. . - ee Species No. 4. 
Pronotum with a sharply defined nearly pure white mesial vitta extending to apical 
declivity of elytra, being constricted in the middle of the latter; pronotum 
rugate allover . . . 2. 2... ww . ~ s+ + « . « Species No. 2. 
As before, but the mesial vitta less contrasting with the sides ; ; antecoxal groove 
of prosternum broad, almost straight, not angulate in middle . . . . . Species No.3 
Pronotum rugate only in the depression . . . . . . «+ «© «© «© © « + Species No. 1. 
1. Ptychoderes tricostifrons. (Tab. X. figg. 1, 1a.) 
Ptychoderes tricostifrons, Fahr. in Schoenh. Gen. Spec. Cure. v. p. 158. n. 4 (1839)'; Jekel, Ins. 
Saund. i. p. 53 (1855) *. 
Hab. Mexico!, Toxpam (Sal/é), Bobo (Hodge), Mochitlan in Guerrero (Baron), 
Ventanas in Durango (forrer), Temax in N. Yucatan (Gaumer); British Honpuras, 
Rio Sarstoon (Blancaneaux); GuatemaLa, Chacoj in Vera Paz, El Tumbador, Las 
Mercedes, El Reposo, Cerro Zunil, Volcan de Atitlan, Pantaleon, Zapote, Mirandilla, 
Rio Maria Linda (Champion); Nicaraeua, Chontales (Belt, Janson); Costa Rica, 
Bebedero (Underwood, in Mus. Tring); Panama, Bugaba, Volcan de Chiriqui 
(Champion). 
This species is as common in Central America as P. elongatus is in Brazil. ‘The 
series examined shows great individual variation in length, the smallest example 
measuring 7 millim. and the largest 22 millim., head excluded. The width of the 
specimens is also not constant, a difference in the proportional length of the prothorax 
being especially noteworthy. Bright-coloured individuals resemble P. rugicollis, but 
are easily distinguished from that species by the structure of the pronotum. 
2. Ptychoderes rugicollis. (Tab. X. figg. 2, 2a.) 
Ptychoderes rugicollis, Jordan, Stett. ent. Zeit. lvi. p. 122. n. 1 (1893) *. 
The sex-mark on the first abdominal segment of the d is different in position from that of P. tricostifrons, 
being situated much nearer the base of the segment in the present insect. 
Hab. Mexico, Toxpam (Sallé), Bobo (Hége); GuatEMaLa, Zapote, El Reposo 
(Champion) ; Nicaragua, Chontales ! (Belt, Janson, Richardson) ; Costa Rica, Zarzero 
(Schild-Burgdorf, in Mus. Tring); Panama, Bugaba, Volcan de Chiriqui + (Champion). 
3. Ptychoderes mixtus. (Tab. X. fig. 3.) 
Ptychoderes mixtus, Jekel, Ins. Saund. i. p. 57 (1855)*; Gemm. & Har. Cat. Col. ix. p. 2722 
(1872) °. 
Ptychoderes variicornis, Jekel, 1. c. °. 
