JURA. 1 LUMINOUS ANIMALS. 193 



the voyage of Captain Horsbrugh. Monsieur Peron has 

 also described in very splendid colouring a newly dis- 

 covered luminous animal which he calls Pyrosoma atlan- 

 ticum ; and it has more recently been ascertained that the 

 whole of this genus is endowed with the same quality. 

 From Spallanzani we have an account of four luminous 

 Pennatulae ; the phosphorea, grisea, argentea, and grandis ; 

 and he further mentions five luminous marine worms of 

 which he has not ascertained the genera : it has since 

 been remarked that all the Pennatulse possess the same 

 property. Among the worms which inhabit shells, the 

 Pholades have also been observed to exhibit light. 



But amid the various tribes of zoophytes, the Medusa 

 is that in which the greatest number of luminous species 

 has been ascertained ; and of these, many are natives of 

 our own shores. The hemispherica and scintillans have 

 been described by Mr. Macartney at some length, but 

 he appears to have supposed this property much more 

 limited than it will actually be found. On the shores and 

 in the deep bays of the Highlands, particularly in the 

 autumn, many distinct species of this tribe are to be seen 

 in great abundance ; all of them shining with such 

 splendour as to enlighten the sea around. The Medusa 

 pellucens has been described as luminous by Sir Joseph 

 Banks, the noctiluca and densa by Forskahl, and two 

 others of the tribe, of which no specific characters are 

 given, are mentioned by Forster and Spallanzani, the 

 former at the Cape of Good Hope and the latter in the 

 Mediterranean. In Captain Tuckey's recent voyage we 

 are informed that a species of Salpa and one of Scyllarus 

 were determined to be luminous, and that the same pro- 

 perty was observed in many animals of the genera Beroe 

 and Holothuria. Twelve crabs are also mentioned as pos- 

 sessed of it, besides the cancer (Astacus) fulgens, formerly 

 ranked among the luminous animals. 



This enumeration, as far as I know, includes all the 

 marine worms which have been fully ascertained to be 



VOL. II. O 



