PTILIUM.— ACTIDIUM. 147 
This insect differs from the European P. foveolatum in its larger size, broader form, 
plane thorax, and deeper general sculpture; from all other species of the genus in its 
narrow elongate form and small size. 
3. Ptilium tropicum. (Tab. III. fig. 23.) 
Piilium tropicum, Matth. Trans. Am. Ent. Soc. xi. p. 144°. 
Sat elongatum, modice convexum, sat nitidum, rufo-testaceum, pilis brevibus flavescentibus vestitum ; capite 
magno, antice rotundato; oculis magnis, prominulis ; pronoto parvo, quam caput nec longiore nec latiore, 
ante medium latissimo, confertim sat fortiter tuberculato, disco interdum leviter impresso, lateribus antice 
valde rotundatis, postice fortiter contractis, leviter marginatis, margine basali fere recta angulis modicis ; 
elytris quam caput atque pronotum multo longioribus et parum latioribus, apicem versus latissimis, 
confertim sed levissime asperatis, lateribus leviter rotundatis, apice lato, leviter rotundato ; pedibus atque 
antennis brevibus, robustis, late flavis. Long. corp. a lin. =0°50-0°63 millim, 
Head large, rounded in front, finely and closely tuberculate; eyes large and prominent ; antenne short, very 
robust, bright yellow, with the ninth joint incrassate. Thorax small, not longer or wider than the head, 
widest before the middle, closely and rather strongly tuberculate, sometimes with a faint impression on 
the disc; sides slightly margined, much rounded anteriorly and strongly contracted towards the base ; 
basal margin nearly straight, with the angles moderate. Scuteliwm rather small, triangular, closely 
asperate. lytra much longer and slightly wider than the head and thorax, widest near the apex, very 
finely and closely asperate; sides faintly rounded; apex very broad and slightly rounded. Abdomen 
with the pygidium only exposed. Legs short, robust, bright yellow. Underparts rufo-testaceous, with 
the mouth and coxe bright yellow. 
Hab. Panama, Bugaba (Champion). 
Differs from P. planum in its smaller size, shorter form, short and very robust 
antenne (of which the ninth joint is more incrassate than usual in this genus), and in 
sculpture. 
Found in abundance at Bugaba. 
ACTIDIUM. 
Actidium, Matthews, Ent. Monthly Mag. v. p. 12 (1868); Trich. Illustr. p. 86, t. 7 (1872). 
Body subovate and very shining, or linear and clothed with dense pubescence. Head large, sessile, and promi- 
nent ; eyes generally large and prominent. Thorax small, cordate, the base rounded and overlapping the 
shoulders of the elytra. Scutellum rather small, triangular. Hlytra entire, often very long and narrow. 
Antenne 11-jointed, generally long, with the two basal joints very large, the intermediate rather slender, 
and the last three forming a slightly incrassated moniliform club, with the ninth joint much smaller 
than the tenth. Palpi: mawvillary long, 4-jointed, with the third joint very large, ovate, not truncate, 
and the fourth aciculate, very slender, and strongly sinuated ; Jabial small and slender, 3-jointed, arising 
from large ovate labial processes ; apical joint very small, acutely pointed. Prosternum large ; episterna 
small and narrow; epimera moderate, very distinct, not enclosing the coxal cavities; coxal cavities 
contingent, open posteriorly. Mesosternum long, broadly elevated in the middle, and produced into a 
sharp point between the coxe ; episterna humeral and narrow ; epimera very large, extending to the 
coxal cavities; coxal cavities oblique. Metasternwm very long, not extending to the sides of the body, 
produced and bidentate between the posterior coxee; episterna very narrow, rather more than half as long 
as the metasternum ; epimera narrow, extending rather beyond the metasternum ; posterior coxe long and 
narrow, not extending to the sides of the body. (In some species the episterna and epimera are concealed 
by the inflexed sides of the elytra.) Venter composed of seven segments, the basal segment being the 
U* 2 
