HOUTMAN’S ABROLHOS. 145 
has commenced to grow retrogressively from its broken end. The original 
axial corallite has in this manner developed a shoot about three-quarters of an inch 
long, from which numerous lateral corallites have also commenced to bud. 
Mention has been previously made of the close resemblance of this purple-tinted 
Stag’s-Horn Coral to the Madrepora hebes of the Queensland coast. As an illustration 
of the correspondence that may be observed in their respective growth plans, 
a photograph of a tidally exposed reef area, consisting almost exclusively of that 
variety taken by the author in the vicinity of Lark Passage on the Great Barrier, 
is reproduced on page 144. Additional reef views embodying the same type will be 
found in the writer’s volume especially descriptive of the Great Barrier Reef products. 
The coral on this Queensland reef lacked the brilliant tints of the Abrolhos colony- 
stocks, being for the most part of a warm brown hue with whitish tips. Some few of 
the coralla among the mass were, however, brilliant green or lilac, while in other 
localities the same species was met with in which the greater portion of the coralla 
was bright grass-green, but every branch tip to the extent of about half-an-inch, 
an intense violet. As recorded by the writer in the volume above quoted, the colour 
characters of the Madreporide are not only exceedingly variable in the same species, 
but are even unstable in individual coralla. Thus a colony-stock of the type under 
notice, Madrepora hebes, growing in a pool at Thursday Island, Torres Straits, 
was, when first observed, made up of pinkish-brown stems and branches with 
greenish-white tips, while the polypes were all ofa light emerald-green tint. On examin- 
ing the same growths two years later, it was observed that the branches and main 
stems were now a dark seal-brown and their tips, to a large extent, a pale lilac-blue 
tint, while the polypes had assumed, for the most part, a clear red-brown hue. It 
is consequently quite possible that the reef areas in Pelsart Island Lagoon here 
portrayed, may at some future date be found to have exchanged the purple tints 
recorded in 1894 for more sombre brown or brilliant green. 
Next to Madrepora, the genus Montipora builds up the most conspicuous coral 
developments in Pelsart Island Lagoon. Its members are chiefly of either an encrusting or 
a foliaceous character, and in many instances of the most brilliant violet or even magenta 
hue. Selected specimens, quickly dried in a breeze, still in the writer’s possession, have 
retained for over two years much of their pristine splendour, and exhibit sufficient of 
their original tints to convey to the untravelled a faint idea of their living beauty. One 
species of this genus Montipora, apparently new to science, but identical with a type 
collected by the writer also at the Palm Islands on the Queensland coast was notable 
T 
