380 



but it does not seem probable that such a property (if it existed) 

 could be overlooked in an animal so extremely common. 



The luminous property of the Pholas dactylus was observed by 

 Pliny to be communicated to the hand that touched it ; and this has 

 been confirmed by Reaumur. 



Of the genus Elater there are three species luminous, one of which, 

 the noctilucus, is so brilliant, that it was employed by the South 

 American Indians for the purposes of illumination. 



In the genus Lampyris there are many species, at the head of which 

 is the Lampyris noctiluca, or common glow-worm, which may serve 

 as a specimen of the manner in which the light is produced by the 

 rest. In this species the light lasts only during the breeding season ; 

 and as it is confined to the female insect, it would appear to answer 

 the purpose of guiding or inviting the male. But it has been observed 

 by Montbeillard, that the eggs are also occasionally luminous ; and 

 Mr. Macartney confirms this observation, as he once saw a quantity 

 of them shine unremittingly for several days together. 



Of the genus Fulgora, only three have been particularly noticed 

 for the light they yield, the lanternaria, candelaria, and pyrorhyn- 

 chus ; although it is probable, from their structure, that many others 

 of the genus possess this property. 



The Pausus is remarkable only for the situation of its light, which 

 is carried at the extremity of its antennae. 



The Scolopendra electrica is not uncommon in this country ; and 

 yet the light has not often been observed. According to the author's 

 observation, the light is communicated, and remains visible for some 

 time on a hand that has touched it ; and, in one or two instances, 

 insects which had been long confined from the light did not appear 

 luminous, but acquired this faculty after being for some time exposed 

 to daylight. 



The Cancer fulgens was discovered by Sir Joseph Banks, who ob- 

 served that its whole body was illuminated, and produced very vivid 

 flashes of light. 



Of the Monoculi, the author reckons three species that are lumi- 

 nous ; one discovered by Godeheu de Riville, and two by Capt. Hors- 

 burgh. 



With respect to the Nereis noctiluca, to which the light of the sea 

 has been ascribed by Vianelli, Griselini, Spallanzani, and others, in 

 various parts of the Mediterranean, and by Adleo in the African and 

 Indian oceans, the author is of opinion that it never appears on the 

 coasts of this country, and that the light of the sea, which we most 

 frequently witness, is caused by Medusae. 



Of these, the largest is the Medusa pellucens, discovered by Sir 

 Joseph Banks, along with the Cancer fulgens, in his voyage with 

 Capt. Cook between Madeira and Rio de Janeiro. This is six inches 

 in diameter. The noctiluca described by Taskal is three inches in 

 diameter. 



Another Medusa was discovered by Spallanzani in the Straits of 

 Messina : it is said to be as bright as a torch, and visible at the depth 



