(542 ANNUAL REGISTER, 1810. 



endowed with the property of 

 shining. A fasciculus of the 

 muscles of the corcelet arises in 

 the interior of the oval masses of 

 the luminous substance, but not 

 apparently with any design, as it 

 contributes, with the adjacent fas- 

 ciculi, to move the anterior feet. 



In the elater ignitus, the masses 

 of luminous substance are ex- 

 tremely irregular in their figure: 

 they are situated nearly at the 

 posterior angles of the corcelet, 

 and are more loose in their texture 

 than the oval masses of tlie nocti- 

 lucus, resembling rather in com- 

 position the interstitial substance 

 which surrounds these masses in 

 that species. The shell of the 

 corcelet is somewhat thinner, and 

 more transparent along both sides 

 of the margin, than at other 

 places ; but it is not, as in the 

 noctilucus, elevated,and peculiarly 

 clear and thin immediately over 

 the seat of the luminous organ : 

 consequently, the light emitted by 

 tlie elater ignitus cannot be very 

 brilliant. 



I have not been able to procure 

 any specimen of the elater phos- 

 phorea, but from the accounts of 

 naturalists it appears to resemble 

 in every respect theelater noctilu- 

 cus ; indeed I have great doubts of 

 the phosphorea being a distinct 

 species. 



I have had an opportunity of 

 examining, preserved in a moist 

 way, two species of fulgora, the 

 candeiaria and lanternaria. The 

 light in this genus has been ob- 

 served to issue from the remark- 

 able proboscis on the fore-part of 

 the head. This part has always 

 been described by authors as hol- 

 low or empty, which I have found 

 to be perfectly correct ; and what 



is more extraordinary, that the 

 cavity communicates freely with 

 the external air, by means of a 

 chink or narrow aperture, placed 

 on each side of the root of the 

 proboscis. This projection is co- 

 vered internally by a membrane, 

 between which and the horny part 

 or shell there appears to be inter- 

 posed a pale reddish coloured soft 

 substance, that is arranged in the 

 candeiaria in broad lines or stripes; 

 but it is so thin, that I could not 

 distinctly examine its structure, 

 or absolutely determine, whether 

 it should be considered as a sub- 

 stance intended tofurnish thelight 

 of these insects, or the pigment 

 upon which the colour of the pro- 

 boscis depends. 



The globes of the antennae con- 

 stitute the organs of light in the 

 pausus spherocerus. Dr. Afzelius, 

 who discovered the luminous pro- 

 perty in this species, compares 

 them to lanterns spreading a dim 

 phosphoric light. The rarity of 

 the insect put it out of my power 

 to examine its structure ; but from 

 the form and situation of its or- 

 gans of light, it is most probable 

 they are constructed like those of 

 the fulgorae. 



It has been conjectured by Car- 

 radori and others, that the lampy- 

 rides were enabled to moderate or 

 extinguish their light, by retract- 

 ing the luminous substance under 

 a membrane ;but neither in them, 

 or any of the other luminous in- 

 sects, have I found an apparatus of 

 this sort. The substance furnish- 

 ing the light is uniformly applied 

 to corresponding transparent parts 

 of the shell of the insect from 

 whence it is not moved ; indeed 

 a membrane, if it did exist, would 

 have but little effect in obscuring 



