PHOIXITYPE PLATES NOS. XXXIII. AND XXXIV. 55 



The polyps which secrete it closely resemble those represented in Chromo plate No. VIII , 

 Fig. 3, being delicate apple-green in hue, and protrusible to long distances beyond their coral 

 basis. A little to the rear of the larger colony-stock of this species are several corymbiform 

 coralla of the brilliant lilac Madrcpora gemmifera. 



(B.)-LflDY ELLIOT ISLSND REEF, WITH EXTENDED BECHE-DE-MER. 



Lady Elliot Island reef, delineated in this plate, is interesting, in addition to the associated 

 Bfiche-de-mer, on account of its belonging to the most southern coral islet of the Great Barrier 

 system. It lies in lat. 24° 5" S., a little south of Bustard Head, is elevated some eight or ten 

 feet only above high-tide line, and is the site of a substantial lighthouse. The corals entering 

 into the composition of the reef include a number of species identical with those recorded in 

 association with the Port Denison reefs; Madrepora millcpora, Pocillopora dainiconiis, Lopltoscris 

 cristata, and a species of Civloria being most conspicuously visible. Long-spined Diademae and 

 Frilled Clams, Tridacna compressa, referred to in association with the Palm Islands reefs, were 

 abundant on this reef. 



The attenuate, fully-extended Beche-de-mer in the foreground of this picture represents 

 one of the commonest Barrier Reef species, Holothuvia afra. It is, unfortunately, of little com- 

 mercial use, shrinking up to an almost hollow skin when boiled and smoked in the ordinary 

 manner; but it is, nevertheless, occasionally blended in small quantities with the better sorts by 

 unscrupulous dealers. It is possible, with the aid of the hand-lens, to distinguish the individual 

 outstretched tentacles of the specimen here illustrated. As may be observed, its hinder 

 extremity is inserted within a crevice of the coral rock, into which, on being disturbed, it 

 speedily retreats. In like manner it not unfrequently happens that a dozen or more individuals 

 of this species may be seen protruded to their full length from beneath a hollow coral rock. Such 

 abundant development of the species is, however, most conspicuous farther inshore, where there 

 are but few growing corals, and where the reef is strewn with rock masses torn off and trans- 

 ported from the outer edge of the reef. In all cases, as in the specimen here illustrated, the 

 extended bodies are seen to lie in shallow water. 



PLATE XXXIV. 



¥IRIETIES OF TREPING OR BECHE-DE-MER. 



This plate illustrates the life aspects of three species of Trepang or Beche-de-mer, two of 

 which, Nos. I and 3, are extensively collected and prepared for the Chinese market, while 

 No. 2 is disqualified in the same manner as the variety associated with the preceding plate, in 



