MON. 251 
MCEON. 
Mentum, palpi, and labium much as in Eprcalla; mandibles cleft at the apex; antenne rather long, the joints 
slightly widening and lengthening outwardly, longer than broad, joints 3 and 4 subequal in M. isthmicus, 
joint 4 a little shorter than 3 in WM. panamensis, each about twice as long as 2, the apical joint much longer 
than the tenth, not widening outwardly, and subacuminate at the apex; head short, the epistoma limited 
posteriorly by a more or less deep transverse impression, truncate and projecting beyond the sides in 
front, separated from the labrum by a membranous clypeus; eyes small, rounded, widely separated ; 
prothorax convex, transverse, the sides strongly, and the base in the middle shallowly, margined, the 
lateral margins reflexed, narrowly grooved within, and not quite reaching the posterior angles, the base 
bisinuate, and with a deep fovea on each side; scutellum moderately large, broad, subtriangular ; elytra 
long, convex, broader than the prothorax, narrowly margined, rounded at the shoulders, the humeri distinct 
but obtuse, subparallel, punctate-striate ; legs moderately stout, smooth, the anterior tibisee on the inner 
side towards the apex clothed (as in Zpicalla) with short silky hair, the tibial spurs very short and almost 
obsolete ; the first joint of the posterior tarsi short, the length of the two following joints united, but much 
shorter than the apical one; prosternum broad, horizontal, longitudinally impressed in the middle, the apex 
strongly produced and abruptly acuminate ; mesosternum concave, the sides narrowly raised ; metasternum 
long; intercoxal process broad, triangular; epipleure ending abruptly at the last ventral suture; form 
oblong ovate, convex ; body glabrous, polished and metallic, winged. 
This genus, separated by Mr. F. Bates under a preoccupied MS. name, contains two 
closely allied species from the Colombian State of Panama. eon may be known 
amongst its allies by its small, rounded, and widely separated eyes, the cleft mandibles, 
the structure of the antenne, the convex thorax (the reflexed lateral margins of which 
are abbreviated behind and do not quite extend to the posterior angles), the long 
convex elytra, the shortened epipleure, &c. 
1. Mcon isthmicus. 
Oblong ovate, convex, greenish-bronze, very shining. Head finely, shallowly, and sparingly punctured, the 
front broadly flattened, the transverse impression deep ; prothorax strongly rounded at the sides anteriorly, 
the sides very feebly sinuate (almost straight) behind the middle, the anterior angles rounded, the hind 
angles thin and subacute, a transverse sinuous groove (shallow on the disc but very deeply impressed at the 
sides and there confluent with the deep basal foveze) some distance before the base, the surface very sparingly, 
shallowly, and finely punctured ; scutellum smooth ; elytra widest in the middle, subparallel, transversely 
impressed on each side below the base, narrowly but deeply punctate-striate throughout, the punctures 
fine and closely placed, the interstices smooth and towards the apex distinctly convex, of a lighter eneous 
tint than the head and prothorax and without greenish reflections; legs dark greenish-bronze, the antennse 
dark ferruginous; beneath dark greenish-bronze, shining, almost smooth, the ventral surface shallowly 
and irregularly wrinkled. 
Length 9 millim. (¢.) 
Hab. Panama, Obispo (Salvin). 
One male example. 
9. Mceon panamensis, (Tab. XI. figg. 10,2; 10a, labium; 10, maxilla and 
maxillary palpus.) 7 | 
Closely resembling M. isthmicus, and differing as follows:—The antenne darker; the prothoracic impressions 
shallower; the elytra more convex and less parallel, the strie finer and much more lightly impressed, 
] 
2KK 2 
