COLEOPTEKA. 
55 
$ Mujores: Antennis corpore longioribus, parum crassis, articulis cylin- 
dricis, parum clavatis, clava elongatissima , angustissima , articulo 
ultimo elongato, deplanuto, versus apicem paullo angustato, apice 
rotundato ; elytris versus apicem evulenter angustatis. 
A Duplo minores: Antennis medium elytrorum superantibus; clava 
latiure , articulo ultimo oblongo-acuto , apice obtuse rotundato; 
elytris versus apicem minus angustatis. 
9 Antennis medium thoracis attingentibus; clava lata , articulo ultimo 
ovato subconico, apice obtusissime rotundato; elytris apicem versus 
baud angustatis. 
Longit. (rostr. incl.) 6f—Ilf lin. = 15—26 millim. 
Latit. hum. If—2f lin. = 3 T |—6^ millim. 
Patria: Cayenna. 
General shape of body of Pt. viridanus , Sch., being, like that species, 
proportionally broad and short, convex and scarcely depressed on the 
elytra, but differing in the elongate shape of the rostrum, and the posterior 
callosity characterizing the first group. 
Head short behind the eyes, more conically narrowed towards the 
rostrum than in Pt. tricostifrons, also slightly more convex in front, 
with the ridges obsolete. Eyes rather convex, more closely approaching 
towards the rostrum than in all the preceding species. Rostrum some¬ 
what narrowed at the base, broader and shorter in the females, a little 
less elongate than in Pt. tricostifrons; base transversely but shallowly 
impressed. 
Thorax rather broad, in the males one-sixth, in the females hardly 
longer than wide; sides more rounded than in all the preceding species; 
base thinly margined, subtruncate; posterior carina narrowly interrupted 
in the middle: disc slightly transversely impressed near the apex, rather 
widely but shallowly depressed above the base, leaving the median area 
between these two impressions somewhat transversely elevated. In these 
latter characters this part of the body approaches nearer to that of the 
last-mentioned insect than to the other previous species (in which the central 
area is hardly perceivable, the depression being nearly longitudinal), but in 
a slighter degree. 
Elytra conjointly very shallowly emarginate at the base, margin 
