CIIASMO'DIA, a genus of Coleopteroua Insects of the section Lamellicorna (Scaraba-us, Linn.), and sub-section aylophili (Latreille). The species have the following characters :—Body rather convex and broad ; acutellum large, somewhat triangular, equalling in length at least one-third, of that of the elytra; the mesosterninn is prolonged into a blunt point, and extends as far as the base of the femora of the anterior pair of legs ; the mandibles are entire, and obtuse at the apex ; maxillae with only two teeth, and furnished with a tuft of fine hairs at the extremity ; mentum elongated) ; elytra shorter than the abdomen, broad behind, and obtusely rounded. The male Chasmodia has the upper claw of the fore tarsi very broad and bifid, or divided at the apex ; the inner claw is small and entire ; the claws of the four posterior legs are entire, and of large size. The female has all the claws Of small size; those of die anterior pair of legs simple ; the four posterior legs have the outer claw bifid. Thu tarsi of the male are thicker than in the female, particularly those of the anterior pair of lege.
All the species of thin genus are of large size, and may be readily distinguished from the Cetonim by their large scutellum and convex form, combined with their smooth and glossy appearance. The thorax is convex, and has the posterior margin considerably waved ; the part joining the stadium has a segment of a circle as it were cut out to admit the fore part of the latter, which is rounded ; this character is also observed in the genus atonia and 211aeraspia, and afforda a good point of distinction between these and the groups nearest allied. The genus Maeraspis has also a very large scutellum, but ditnrs in the tarsi and other parts. placitasets.) Chasmodia riridis is about an Inch in length and of a deep blue green colour throughout, with the exception of the ants:me, the basal joints of which are pitchy-red, and the club is black.
There are four other species knowu, some of which are of a glossy brown or chestnut colour. They all inhabit South America. The species above named is common in collections from the Brazils.