EUNICIDJ5. 349 



found the same form phosphorescent in the Maldives. Eunice siciliensis, which some 

 consider a borer, is stated by Mr. Crossland also to be phosphorescent. 



The distribution of the BunicidaB is world-wide, though they are apparently most 

 plentiful in the warmer seas. They range from tide-marks to 1240 fathoms. 



Their food consists of both vegetable and animal structures — chiefly invertebrate — 

 with sandy mud and its contents. 



The majority of them secrete tubes, and some of these are branched. Others frequent 

 holes in the limestone rocks, e. g., Eunice siciliensis, and some on this account have been 

 credited with the power of boring in solid, hard substances as do the Eunicids found in the 

 telegraph cables, but, as elsewhere stated, 1 there is as yet no direct proof that they do 

 so. Mr. Crossland has recently found both Eunice and Lysidice common in the coral 

 blocks of the Reel Sea, and perhaps may be able to clear up the ambiguity on this point. 



Under this family fall the most conspicuous representatives of the "Palolos" of 

 foreign seas. These have already been alluded to in the ' Challenger ' volume 2 as well as 

 subsequently, 3 and it need only be added in connection with the Atlantic " Palolo " that 

 an explanation of the remarkable absence of heads is afforded by the recent observations 

 of A. Gr. Mayer, 1 who found that the ripe examples of Eunice fucata turn tail outwards 

 in their tunnels in the coral and limestone rock and detach the tail-end containing the 

 reproductive elements. These swarm at the surface, and shed, as the sun rises, their ova 

 or sperms by rupture or otherwise, whilst the shrivelled remnants fall to the bottom and 

 perish. The adults in the tunnels regenerate their tails. In this form the males are 

 orange posteriorly, the females greenish. Moreover Lysidice oeelef the " wawo " of 

 Amboina, in the Malay Archipelago, leaving its retreat, swarms on the second and third 

 nights after full moon in March and April. 



The group of the Eunicidaa is one in which representatives of two divisions (E. 

 labidognatha and E. labidognatha nuda) are found in a fossil condition in the Solenhofen 

 slates, the genera being termed respectively Eunicites and Lumbriconereites® In both 

 instances the form of the dental apparatus considerably differs from that of the living 

 types. These fossil forms range back to the Silurian rocks of the United States, Canada, 

 Eno-land (Wenlock and Ludlow formations), Scotland, and Scandinavia, and a great 

 variety of minute jaws has been described and figured by Dr. George Jennings Hinde. 7 

 Comparatively few examples of the maxillse occur, the majority consisting of the great 

 dental plates, or of the antero-lateral plates. Not a single example of the mandibles 

 has been found, so that Mr. Hinde considers these ancient forms were devoid of them, 



1 ' Challenger/ vol. xii, Annelida, p. 262. 

 3 Ibid., p. 257, 1885. 



3 ( Ann. Nat. Hist./ ser. 7, vol. xv, p. 33, 1905. 



4 Carnegie Instit., Washington, vol. i, pp. 107 — 112, pi. i, 1908. A similar condition is described 

 by Percy Moore in Eunice paloloides at San Diego (' Proc. Acad. Nat. Sc. Pliilad./ June, 1909). 

 Recently (April, 1910) Treaclwell lias found that moonlight is not necessary for the swarming of 

 Eunice furcata. 



5 R. Horst, 'Mus. Harlem/ pp. 105—108, 1905. 



6 Elders, l Ueb. foss. Wiirmer/ Cassel, 1869, and ' Zeitschr. f. wiss. Zool./ xviii, p. 421, 1868. 



7 'Quart. Journ. Geol. Soc./ August, 1880, p. 368, pi. xiv; and ' Bihang till k. Svenska Vet.- 

 Akad. Handl./ Bd. 7, No. 5, p. 1, pis. i— iii, 1882. 



