128 ON THE LITTORAL FAUNA OF N. E. AUSTRALIA, 



to witkdraw immediately, and a closed appearance was very- 

 manifest over a considerable area of the cells. There must be 

 millions on each one of the round fiat tabular masses of Porites, 

 which are so common on the reefs. These ''tables" are quite 

 loose and can be turned over without difficulty. They are seldom 

 more than a foot thick and the under surface is like the upper. 



I have reserved for the last any mention of the Holothuridcd 

 which give such a commercial importance to the reefs at the 

 present time. Any detail on the subject of species would require 

 a special essay. So much has been done by observers in Europe 

 — especially northern Europe — that to examine our Australian 

 species under the light of these investigations would be an 

 extensive undertaking. I trust that the time is not distant when 

 it may be done, but I dont think it can be done unless on the 

 reefs themselves, where anatomical examinations of the living 

 examples will alone furnish the required facts. I merely record 

 now that the species collected in abundance are those classified 

 as Trepang by Q-. F. Jaeger, in 1833 in the well known essay De 

 Holothuriis.^' The genus is not adopted, and has no better 

 definition from its author than "body sub-cylindrical, mouth 

 anterior, surrounded by ten to twenty x)etately capitate tentacles." 

 He enumerates four, viz. Trepang edulis, T. ananas^ T. impatiens, 

 and T. peruviana. The first of these is certainly found on the 

 reefs, and is called by the fishermen '' red fish." It is an 

 elongated oval, somewhat shapeless mass of dull, reddish-brown 

 color, and covered all over with papillary suckers. It is eight or 

 ten inches long and very heavy. Next to this is the '' tit-fish," a 

 somewhat smaller species of elongated shape, black in color, and 

 studded with somewhat distant, large tentacles, which project 

 nearly an inch or so. Another species is the "milk-fish," or 

 " cotton- fish," so called from its power of emitting a white viscid 

 fluid from its skin, which clings to any object like shreds of 

 cotton. The fishermen do not use it, and it is said that the white 



* De Holo. Dissertatio inaug. Turici, 1833, 4 to with plates. 



