124 LONGICORNIA. 
TRACHYSOMUS. 
Trachysomus, Serville, Ann. Soc. Ent. Fr. 1835, p. 40. 
Seven species of this distinct and remarkable genus have been recorded from Tropical 
South America. It has not hitherto been known as represented in the part of the tro- 
pical zone north of Colombia. 
1. Trachysomus fragifer. 
Lamia fragifera, Kirby, Trans. Linn. Soe. xi. p. 440. 
Hab. Mexico, Juquila (Sai/é).—Sourn America, Cayenne to South Brazil. 
A specimen in M. Sallé’s collection does not differ from examples from South Brazil. 
The species is widely distributed; but in the Amazons region it occurs in a slightly 
modified form. 
ONCIDERES*. 
Oncideres, Serville, Ann. Soc. Ent. Fr. 1835, p. 67 ; Lacordaire, Gen. Col. ix. p. 677. 
Nearly fifty species of this fine genus of American Lamiade have been described, the 
great, majority of which are confined to the tropical zone, a few only, of diminished size, 
occurring in temperate latitudes, in the regions of the La Plata in the south, and in the 
Atlantic States in the north. One species, 0. amputator, Fab. (=lherminieri, Forsstr.) 
is found in the West Indies. | | | | 
Lacordaire dwells, with good reason, on the heterogeneity of the contents of the genus 
as at present defined. Some of the divergent points of structure seem to me only of 
specific rank; but others are more important, and point to the existence of two natural 
groups. In one group, of which O. callidryas may be taken as the type, the general 
form is much less cylindrical and less convex, the thorax in both sexes as wide or wider 
behind than in front, and the frontal horns of the male porrect. This group is very 
closely allied to Zybalmia. In the second, or typical, group, the form is cylindrical 
and convex, and the thorax (especially in the female) narrower behipd than in front: 
The first section is almost of generic rank, and may be distinguished by the name of 
Lochmeocles. 
Section i. LOCHMAOCLES. 
1. Oncideres callidryas. (Var. 2, Tab. IX. fig. 9.) 
- Oncideres callidryas, Bates, Ann. & Mag. Nat. Hist. 1865, xvi. p. 175. 
Var. 
Elytrorum maculis fulvo-ochraceis, minus discretis, plus minusve difformibus et confluentibus. 
Hab. Var., Nicaracua, Chontales (Belt, Janson).—Typ., Sourn America, Amazons. 
* The founder of this genus, and inventor of the name, made it feminine. 
