218 CLASS VII. 



asserted that this phenomenon has been occasionally observed in 

 the earth-worm (Lumbricus terrestris L.) It is quite certain that it 

 has been seen to occur in very many marine Annelides: and hence 

 these are creatures also which contribute to the illumination of the 

 sea. Nereidce are especially noted in this respect : DUGES observed 

 the phenomenon in a Mediterranean species 4" long, Syllis fulgu- 

 rans 1 . QlJATREFAGES made the important discovery that, in certain 

 minute marine Annelides (species of Syllis and Polynoe), the seat of 

 the phenomenon is at the base of the feet-tubercles in fact in the 

 muscles: it was only when the muscles contracted that the light 

 appeared like an electric spark 2 . 



Ringed-worms are found in all countries and seas : but it is im- 

 possible to present a view of the geographical distribution of the 

 species hitherto known, for this class is perhaps more generally 

 neglected by voyagers than any other, and we are acquainted with 

 few marine annelides except those from the Atlantic ocean, the 

 Mediterranean, and the Red sea. Of the genus Palmyra only one 

 species is known, which was found at the Mauritius. From the 

 Indian sea some large and beautiful species are known, as Laodicea 

 gigantea; Serpula gigantea is from the West Indies : and, in general 

 the large and beautiful species are most numerous in warm regions. 

 Some species appear to have a very wide geographical distribution, 

 as Hesione splendida, found by SAVIGN Y in the Red sea, and brought 

 by MATTHIEU from the Island of Mauritius : and Pleione carunculata, 

 which, according to PALLAS and SAVIGNY occurs in the American 

 seas, according to SEBA in the Indian sea, and was found by GRUBE 

 in the Mediterranean at Sicily. The Hirudinea and Lumlricini 

 have scarcely been investigated elsewhere than in Europe. 



1 Ann. des Sc. not. Tom. xxix. p. 229. The Nereis noctiluca L. is a small animal- 

 cule, probably the same species as Nereis cirrigera of VIVIANI. Polynoe fidgurans, at 

 most half a line long, was observed and figured by EHKENBEKG, Leuchten des Meercs, 

 Tab. i. fig. r . 



2 Ann. des Sc. not. sec. S^rie, xix. 1843, Zooloyie, pp. 183 192. 



