PHOTOTYPE PLATE NO. II. 7 



vegetable skeletons consist, possess intrinsic features of beauty that in their special order can 

 scarcely be surpassed, but are, at the same time, not comparable in hue and aspect with the 

 same skeletal elements clad with their exquisitely-tinted living tissues. 



PLATE II. 



CHSRTED REEF, THURSDSY ISLAND, TORRES STRfilT. 



This first number of the series of reef-views, while by no means as attractive in aspect as 



many of the succeeding illustrations, possesses a specific value that claims for it a prominent 



position. It represents an area of reef, of the ordinary inshore or fringing variety, at the extreme 



[ south or seaward end of Vivien Point, Thursday Island, as exposed at an abnormally low spring- 



: tide on June 9th, 1890. Throughout the greater portion of the year, including all ordinar}' 



springs and neaps, the larger portion of this coral-growing area is completely submerged. 



It occurred to the author that this area, being situated in so readily-accessible a position, 

 immediately outside the grounds of the Government Residence, Thursday Island, offered excep- 

 tional facilities for recording the much-needed data concerning the average rate of growth of the 

 more important reef-forming coral species. Upon this subject there has hitherto been very little 

 accurate information available. For the acquirement of such knowledge it is requisite that 

 healthy coral-growths should, in the first instance, be selected ; their respective dimensions and 

 bearings with relation to one another should then be accurately determined, and corresponding 

 measurements should be taken at systematic intervals. As an initial step in this direction, the 

 author has made a rough diagrammatic chart of the vigorously-growing reef at the extreme outer 

 edge of the area portrayed in the illustration now under notice. In this chart, the longest 

 diameters of all the conspicuously-growing corals have been accurately measured and registered. 

 An earnest appeal is here made, in the interests of science, to any residents in, or visitors to, 

 Thursday Island, during favourable tides, to identify and measure these coral-masses, and by so 

 doing to ascertain what growth they have made since their first measurement in the year 1890. 



This diagram of the Vivien Point reef-area was first published in association with the author's 

 presidential address to the Royal Society of Queensland for the above-named year ; it is repro- 

 duced overleaf, together with a list of the specific forms oi corals growing on it more detailed than 

 has been previously recorded. This diagrammatically-charted area, with relation to the reef- 

 view, Plate II., applies exclusively to the isolated islet to the extreme left of the reef, and is 

 practically composed of two large coral-masses, separated from one another by a deep and 

 narrow channel. The outermost, or larger, of the two masses consists of a solid growth of an 

 exceedingly minute-celled Porites, identical with, or nearly allied to, P. astrccoidcs ; its character- 

 istic nodular surface-pattern is distinctly visible on the inner right-hand border of the mass in 

 the photographic reproduction. This Porites colony-stock in its longest, diagonal, diameter 



