PTEROCYCLON. 277 
club rather small, oval, with curved sutures. Prothorax oblong, elliptically rounded in front to behind 
the middle, the sides behind nearly straight, the hind angles obtuse, not rounded, the base subtruncate ; 
surface declivous and asperate for the anterior third, with no definite discal elevation, the posterior part 
moderately shining, finely reticulate, and sparsely punctate. Scutellum rounded, rather small. Elytra 
narrower at base than the prothorax and about one-fourth longer, truncate at the base, the shoulders 
obliquely rounded, the sides slightly curved throughout, subampliated towards the middle, and narrowed 
behind ; apical margins obtusely rounded, the median emargination shallow ; surface cylindrico-convex, 
shining, with rows of minute punctures; declivity subvertical, subexcavate but shallow, longitudinally 
curved above and slightly produced along the suture in front, shining, punctured, the lateral margins 
gibbous and subacute below, with two small tubercles on each side, the upper tubercle rearer the suture 
and situated on the margin, the lower just within it. Underside piceous; legs ferruginous-yellow, 
infuscate in part; anterior tibize: with strong marginal serration. 
Hab. GuateMata, Cerro Zunil (Champion). 
One specimen. Similar to P. hoegei, but about half the size, with the prothorax 
devoid of a definite discal elevated line; the punctuation of the elytra is finer and 
hardly perceptible with a lens, the side-margin of the apical excavation is rounded 
before the first tubercle, whereas in P. hoegei it is elevated to form a distinct ridge 
continuous with the upper edge of the tubercle; the punctuation of the fundus is 
much sparser in P. /uctuosum. ‘The type shows a little ferruginous spot at the base 
of each elytron, close to the scutellum, which is probably not a constant character. 
10. Pterocyclon bidens, sp.n. (Tab. VIII. fig. 16, ¢, apex of elytra.) 
Mas. Oblongus, cylindricus, subnitidus, fuscus, prothoracis apice et elytrorum dimidia parte basali dilutioribus ; 
antennis pedibusque testaceis; prothoracis margine apicali tuberculato, disco postice subopaco, obsolete 
punctato ; elytris parallelis, subimpunctatis, ad apicem oblique retusis, marginibus sat distinctis, retusione 
obcordata, ad suturam impressa, lateraliter in utroque elytro tumida et dente valido ad apicem emarginato 
instructa. 
Long. 2°8 millim. 
Male. Oblong, cylindrical, slightly shining, subglabrous. Head rather flat in front, glabrous, rather strongly 
_ punetured laterally, with a scarcely elevated median reticulated line; antenne brown-testaceous, the 
sutures of the club slightly curved. Prothorax almost one-fourth longer than broad, its apical margin 
strongly rounded and regularly tuberculate, the sides subparallel, the hind angles obtuse, the base 
truncate; disc somewhat opaque, fuscous, with an ill-defined darker patch over the anterior third, the 
apex and base paler, the anterior third declivous and convex, without any median elevation, asperate, the 
posterior part with scattered microscopic punctures. Scutellum obtuse-triangular, rounded at apex, 
black. Elytra one-third longer than the prothorax, truncate at base, with rounded-rectangular humeral 
angles, the sides feebly curved and slightly narrowed behind, the apical margins separately rounded, and 
excised to form a broad shallow emargination; surface slightly curved longitudinally, glabrous, sub- 
impunctate, posteriorly obliquely retuse, obcordate, the margins thickened above, becoming well-defined 
and subacute at the sides and below, and with a few minute setiferous tubereles, surface of the retuse 
area impressed along the suture, on each side tumid and armed with a strong vertically-compressed tooth 
directed backwards and inwards and notched at the tip. Underside fuscous, the abdomen lighter ; legs 
testaceous. 
Hab. Panama, Volcan de Chiriqui (Champion). 
One example. ‘This species is well distinguished by the single tooth situate within 
the margin on each side of the elytral declivity, and recalling in form the armature 
met with in some species of Sinorylon among the Bostrychide. 
