Lamellicorn Genus Cryptodus, and its Allies. 23 
Rurzoritatys, West. (Plate II., fig. 3, and details.) 
Subgenus novum, e genere Phileuri. 
Corpus oblongum, subconvexum. Caput subtriangulare, clypeo 
antice acuminato, posticeque tuberculo truncato armatum. 
Antenne breves, 10-articulata, articulo basali latissimo 
depresso. Labrum corneum, ciliatum, pilosum, in medio 
marginis antici emarginatum, angulis anticis rotundatis. 
Mandibule mediocres cornez, apice acute, margine externo 
bisinuatee, in utroque latere clypei porrectee. Mazxille lobo 
apicali acutissimo, dentibus duobus acutis interne armate, 
lobo interno inermi. Mentwm magnum heptagonum, labium 
et articulos duos basales palporum labialium obtegens, 
pone medium elevatum. Pronotum Phileuri, at magis con- 
vexum, sulco profundo medio in parte antica, marginibus 
ejus lateralibus in tuberculum elevatis. Hlytra brevia, sub- 
convexa, irregulariter punctata. Pedes sat breves; ungues 
pedum anticorum inzequales ; onychiis longis, apicé setulo- 
sis; tibiis pedum quatuor posticorum ut in Phileuris armatis ; 
tarsorum articulo basali magno, apice supero in spinam 
acutam producto. 
This insect possesses most of the characters of Phileurus, differ- 
ing from it, however, chiefly in the more convex and irregularly 
punctate habit of the species, the simple inner tooth of the maxille, 
the shape of the mentum, the greatly dilated basal joint of the 
antennz, and the unequal-sized ungues of the fore legs. It will 
be found to agree with Cryptodus in the general structure of the 
mouth, namely, the concealed sub-bilobed labrum, the horny acute 
mandibles, the horny dentate maxillee, the large mentum conceal- 
ing the labrum, and base of the labial palpi; the dissimilar form 
of the fore ungues, the dilated basal joint of the antennz, and of 
the four posterior tarsi: and differing from it in the form of the 
clypeus, the want of a tooth on the inside of the mandibles, and 
on the mner lobe of the maxillz ; in the different shape of the 
mentum, and the more convex body. Dependant upon the form of 
the clypeus, and the comparatively smaller mentum, and large size 
of the mandibles, is the more exposed position of the latter at the 
sides of the mouth, whereas we find them in Cryptodus completely 
concealed by the large clypeus and mentum. 
Rhizoplatys cribraris. 
Piceo-niger, capite antennarumque articulo basali punctis 
