PLOCHIONOCERUS. AT1 
PLOCHIONOCERUS. 
Palpi breves, labiales articulo ultimo parum incrassato. Prothorax elongatus, linea marginali superiore 
subtus divergente ante medium prolongato. 
This genus is established for Sterculia formicaria and its allies. Besides a marked 
difference in facies arising from the different colour and sculpture and the more linear 
form, they differ constantly by the shorter trophi and less dilated rather differently 
shaped terminal joint of the labial palpi, and also by the superior marginal line of the 
thorax ; this latter in true Sterculia is peculiar; on the basal half it limits the superior 
pagina from the side, but about the middle becomes suddenly obsolete and very 
abruptly deflexed, while a false margin of a more or less distinct character is continued 
forwards from the point where the true marginal line is directed downwards. In 
Plochionocerus, on the contrary, the true marginal line is diverted downwards without 
disappearing, and is continued forwards to the prosternum, and there is no false 
marginal line on the anterior part of the thorax. 
Plochionocerus, like Sterculia and Agrodes, is no doubt peculiar to Tropical America, 
and comprises, in addition to the species here mentioned, S. funebris, S. fimetaria, 
S. clavicornis, and S. minor, Sharp. 
Mr. Champion informs me these insects are found running on the roads and paths, 
and look like large ants. 
1. Plochionocerus brachypterus. (Tab. XII. fig. 15.) 
Elongatus, nigro-subzneus, griseo-pubescens, opacus, densissime punctatus; palpis, antennis tarsisque piceis ; 
elytris quam thorax brevioribus, omnium densissime punctatis; thorace linea mediali antice latiuscula 
levigata; abdomine subnitido, minus dense punctato. 
Long. 17 millim. 
Hab. Mexico, Cordova (Sallé), Misantla (Hége); Guatemaa, Cerro Zunil 4000 to 
5000 feet, Las Mercedes 3000 feet, Zapote (Champion); Honpuras (Sallé); Panama, 
Bugaba (Champion). 
Although closely allied to P. formicarius, this species is readily distinguishable by 
the short elytra; it is also less black in colour, and somewhat smaller in size. It is 
apparently a rare insect, for although it has been procured in several localities, only nine 
examples have been obtained. ‘They do not exhibit much variation, except that the 
two individuals from Bugaba are somewhat larger and darker in colour. 
The specimen figured was found at Cerro Zunil. 
2. Plochionocerus formicarius. 
Sterculia formicaria, Er. Gen. et Spec. Staph. p. 304°; ? Lap. Et. Ent. p. 119, pl. 3. f. 32. 
Areocnemus flagellicornis, Nordm. Symb. p. 165°. 
Hab. Costa Rica, Cache (Rogers).—Soutn America !23, Colombia 4, Cayenne !, &c. 
