COLEOPTERA. 375 



observable when they are seized or held in the hand. They live a long 

 time in vacuum and in different g-ases, the nitrous acid, muriatic and sul- 

 phurous gases excepted, in which they soon expire. Placed in hydrogen 

 gas, they, sometimes at least, detonate. They continue to live after the 

 excision of the luminous portion of their abdomen, and the part thus sepa- 

 rated preserves its luminous property for some time, whether it be submitted 

 to the action of various gases, be placed in vacuum, or left exposed to the 

 air. The phosphorescence depends on the softness of the matter, rather 

 than on the life of the animal. When apparently extinct it may reproduced 

 by softening the matter with water. The Lampyrides emit a brilliant light 

 when immersed in warm water, but in cold water it becomes extinguished: 

 this fluid seems to be the only dissolving agent of the phosphoric matter. 

 They are nocturnal Insects. 



In our second division of the Lampyrides, the antennae are very remote 

 at base; the head is neither prolonged nor narrowed anteriorly in the form 

 of a snout, and the eyes are of an ordinary size in both sexes. 



This division consists of the genera Drilus, Telephones, Sills, &c. 



In the third tribe of the Malacodermi, or the MELYHIDES, we find 

 the palpi most commonly short and filiform; mandibles emarginated 

 at the point; the body usually narrow and elongated; the head only 

 covered at base by a flat or but slightly convex thorax, generally 

 square, or elongated and quadrilateral; joints of the tarsi entire, and 

 the hooks of the last one unidentated or bordered with a mem- 

 brane. The antennae are usually serrated, and, in the males of 

 some species, even pectinated. 



Most of them are very active^ and are found on flowers and 

 leaves. 



This tribe, which is a mere division of the genera Cantharis and 

 Dermestes of Linnaeus, will form the genus 



MELYEIS, Fab., 

 Now consisting of the subgenera Malachius, Dasytes, &c. &c. 



The fourth tribe of the Malacodermi, that of the CLERII, is dis- 

 tinguished by the ensemble of the following characters. Two of 

 their palpi at least project and are clavate. The mandibles are den- 

 tated. The penultimate joint of the tarsi is bilobate, and the first 

 is very short or but slightly visible in several. The antennae are 

 sometimes nearly filiform and serrated, and at others insensibly en- 

 larged near the extremity. The body is usually cylindrical, the 



