508 INSECTA. 



[The Brachelytra Lave been investigated oy several recent authors, who have published either com- 

 plete monographs, or descriptions of the species belonging to various countries. In addition to PaykuU's 

 monograph of the Swedish species, published in 1789, and Gravenhorst's Coleopfera Microptera, at 

 Brunswick in 1802, and Monogr. Coleopt. Micropt., 1806, we may mention Count Mannerheim's 

 revision of the tribe, pubhshed in the Transactions of the Imperial Acad. St. Petersburg, 1 831 ; Latreille's 

 memoir on the Denticrura, in the Nouv. Annates du Museum, vol. i. ; Laporte's descriptions of many 

 new species in his Etudes Entomologiques ; Nordmann's work on the Brachelytra, published at Berlin in 

 1838 ; Erichson's description of the Coleoptera of Brandenburg, and his Genera et species Staphylinorum, 

 just published, (December 1839) ; and Mr. Stephens's British Entomology ; in all which works, as well 

 as in numerous detached memoirs by other authors, to which we cannot refer in detail, are contained 

 the descriptions of numerous new species and many new genera, — to speak according to the text of this 

 work, subo-enera, — amongst which some remarkable variations of structure occur, especially in some just 

 figured Ijy Erichson,andZ)«i7tossa, Hal., and Centroglossa and Z'eiwq/jsi*, Mathews, described in l\\& Ento- 

 mological Magazine. We have collected all that relates to the natural history of these insects in the 

 Introduction to the Modern Classification of Insects, vol. i. p. 162. The family Pselaphidae, placed in 

 this work at the end of the Beetles, ought in a natural system to be placed in immediate contact with 

 the Brachelytra.] * 



THE THIRD FAMILY OF THE COLEOPTERA PENTAMERA,— 



The Serricornes, — 

 Also possesses only four palpi, but the elytra entirely cover the abdomen, which, with other characters, 

 distinguishes them from the Brachelytra ; the antenna; (with some exceptions,) are of the same thickness 

 throughout, or slender at the tip, and toothed, serrated, or fan-shaped ; being most developed in these 

 respects in the males. The penultimate joint of the tarsi is often bilobed or bifid. These characters 

 are rarely found in the next family, the Clavicornes, to which we approach so gradually that it is diffi- 

 cult to assign its limits rigorously. 



Some of the Serricornes, having the body always of a solid consistence, and often oval or elliptic, with 

 the feet partly contractile, have the head vertically introduced as far as the eyes into the thorax, and 

 the prosternum, or the middle part of this portion of the body, elongated, dilated, or advanced in front 

 as far as the mouth, (generally distinguished on each side by a canal, in which the antennae, always 

 short, repose,) and posteriorly prolonged into a point which is received in an impression of the anterior 

 extremity of the mesosternum. These fore- legs are at a distance from the anterior extremity of the thorax. 

 These Serricornes form a first section, that of the Sternoxi. 



Others, having the head also received posteriorly into the thorax, or at least covered by it at the 

 base, but of which the prosternum is not dilated and advanced anteriorly like a necklock, nor ordi- 

 narily terminated (except in Cebrio) behind in a point received into a cavity of the mesosternum, and 

 in which the body is generally entirely or partly of a soft and flexilile consistence, compose the second 

 section, Malacodermi. 



A third and last section, the Xylotrogi, comprises those Serricornes in which the prosternum is not 

 elongated at its posterior extremity, and in which the head is entirely free, and separated from the 

 thorax by a narrowed neck. 



We divide the first of these sections, the Sternoxi, into two tribes. 



The first, Bvprestides, has the posteriorly produced part of the prosternum flat, not terminated by a 

 laterally compressed point, and simply received in a depression or notch of the mesosternum. The 

 mandibles are often terminated in an entire point without a notch ; the posterior angles of the thorax 

 are not, or but slightly, elongated ; the last joint of the palpi is generally cylindric, and not thicker 

 than the preceding ; the majority have the tarsi dilated and cushioned beneath. They do not leap, 

 which eminently distinguishes them from the following tribe. They compose the genus 



BuPRESTis, Linn., — 

 And have been termed Richards by the French, in allusion to their splendid colours, many being 



* The Silphffi, in respect to their internal structure, ought, ill conjunction with the other clavicorn Beetles, immediately to follow 

 Brachelytra. 



