BECHE-DE-MER FISHERIES. 241 



On the pearl-shelling grounds of Western Australia, a fish of the same genus lodges within the 

 mantle-folds of the large mother-of-pearl shell, Meleagrina inargarltifcra. An interesting example 

 is exhibited in the shell gallery of the British (Natural Historyl Museum, in which a Fierasfer, 

 having apparently died in this position, has been enclosed by the mollusc within a pearly 

 sarcophagus. 



Figures 8 and 9 of the Chromotype plate No. XII., delineate organisms that do not precisely 

 coincide in aspect and structure with the typical Beche-de-mer, most abundantly represented in 

 this plate These are technically known as Synaptae, and belong to a generic group, whose 

 members, while allied to the ordinary Holothuriae, differ from them in the composition of their 

 oral tentacles. These organs are fewer in number (ten only) and pinnate, like the fronds of a fern, 

 while the animals themselves are altogether devoid of the characteristic locomotor tubules and 

 acetabula so conspicuously associated with the more familiar forms. In lieu of these, the surfaces 

 of the integument of the Sjmaptae are roughened by the presence of countless myriads of minute 

 calcareous spicules, often wonderfully like anchors in shape, by means of which these animals 

 hook on to, and literally " warp " themselves over, the surface of the ground they elect to traverse. 

 There is one allied genus, Chirodota (more abundantly represented, however, on the South 

 Australian coast-line), which presents the remarkable phenomenon of an animal beset, as it were, 

 by wheels, the armature in that type being represented by the most exquisitely-fashioned, six- 

 rayed, wheel-like spicules. The species of Synapta, S. Bcselii, depicted in Fig 8 of the Chromo- 

 plate XII., is the largest known member of its tribe, not unfrequently stretching out on the 

 reef-flats covered with the Zostera-like grass, Posidonia anstralis, to a length of five or six feet. 

 It is also remarkable for the symmetrically nodular, quadrangular, pattern of the plications of 

 its integument shown in the figure. Under the condition of fullest extension, however, these 

 nodular rugae may become entirely, or locally, obliterated, reappearing again when the animal 

 contracts into its normal condition of repose. Its skin, in common with that of other members 

 of the genus, is excessively thin and semi-transparent, almost permitting a vision of the enclosed 

 viscera. This handsome species, was found most abundantly on the extensive Warrior Island 

 reefs in the north of Torres Strait, and also, more sparingly, as far south as Rocky Island, off 

 Cape Flattery. Different individuals, as with many of the ordinary Holothuria;, vary con- 

 siderably in their colour-patterns, some being brighter, others darker, or more variegated than 

 the example figured. 



A characteristic illustration of the colour variation to which the members of this group are 

 subject, is afforded by the cluster of a smaller, smooth-skinned species of Synapta (Fig. 9), deline- 

 ated to the right of S. Beselii (Fig. 8). No two of these individuals are alike, being either self- 

 coloured, striped or diversely speckled. All five, with other additional specimens, were brought 

 up by the dredge, in a tangled mass, in Cleveland Bay, off Townsville. A more typical, brilliantly- 

 tinted species of Holothuria, Colochirus anceps, is represented by Fig. 4 of this same plate. This 



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