MARINE MISCELLANEA. 217 



distended with water, distinctly reveal their organic character. Otherwise, the upper 

 portion of these illustrations might pass muster as depicting scenery from the stalactite 

 caves or grottoes of Derbyshire. Seen at close quarters, these Ascidians are of 

 gelatinous consistence and of a transparent grey hue, sprinkled throughout their lower 

 inflated areas with minute bright blue spots. These spots, examined with the aid 

 of the microscope, are found to represent the separate bodies of the many hundred 

 zooids or individuals that are colonially associated in each of the hanging ovate masses 

 or capitula. 



The exceedingly roughened character of the upper surface of the rocks in the 

 views under notice is also attributable to the accumulation of organic entities. Each 

 minute excrescence that contributes towards the general roughness is, in point of 

 fact, the conically-pointed shell of a species of Barnacle or Acorn Shell, and they 

 are, in many instances, piled one upon another in serried aggregations. Another 

 animal group which, while unobserved on the Queensland coast, is very conspicuous 

 in Roebuck Bay, is that tribe of the Alcyonaria, or soft flexible corals, that includes 

 the genus Spoggodes, and its allies. Examples of the type most abundant in the 

 vicinity of the rock scenes here illustrated were observed in their contracted condition, 

 when the tide was down, to present a symmetrically spheroidal contour, with all their 

 characteristic elongate, sharply-pointed, calcareous spicules projecting from the periphery 

 of the sphere, like the spines of an Echinus or Sea Urchin. They are, doubtless, under 

 these conditions effectively protected against the attacks of wading birds, crabs, or 

 any other ordinary enemies to which they might otherwise be exposed when left high 

 and dry or covered by but a thin sheet of water. The transformation of these 

 spheroidal spinous masses of Spoggodes, when kept in sea-water, into erect, tree-like 

 growths, in which the most delicate transparent tints of pink, lilac and pale yellow 

 predominated or were variously combined, was a marvellously fascinating spectacle. 



A very striking feature of some of the reef pools, at Entrance Point, in 

 Roebuck Bay, was the brilliant pink and yellow hue of certain organisms that 

 bestrewed the rock surfaces. These were in places so closely crowded together as 

 to constitute continuous patches of several square yards in extent. On near examina- 

 tion it was found that the component units of these colour patches consisted 

 of a species of Holothuria or B6che-de-Mer, technically named Colochirus anceps. 

 This variety, which was obtained sparingly by the writer with the use of the 

 dredge in Torres Straits, North Queensland, would appear to find the conditions 



on the tropical Western Australian sea-board especially favourable to its growth 

 EE 



