Chap, xi.] TRIGONIA AND CESTRACION. 239 



The hand marks have evidently ])een made haphazard, just 

 as the drawings. They are now often out of easy reach, the 

 former floors of the caves having slipped away. They are 

 grouped in all sorts of ways, and amongst them I saw one in 

 which a finger was missing, the native having possibly had a 

 finger cut off as a matter of ceremony. The figure of a whole 

 man is said to exist thus executed, in Cowan Creek, close by. 



Delightful though it was at Sydney to make so many friends 

 amongst one's countrymen, after so long a voyage from home, 

 and to enjoy their far-famed hospitality, one could not, as a 

 naturalist, help feeling a lurking regret that matters were not 

 still in the same condition as in the days of Captain Cook, and 

 the colonists replaced by the race which they have ousted and 

 destroyed, a race far more interesting and original from an 

 anthropological point of view. 



Whilst we were at Sydney, the ship's steam pinnace was 

 constantly employed in dredging for Trigonia shells in Port 

 Jackson. These shells, in shape very like cockles, are imme- 

 diately known by their brilliant pearly lustre within, and 

 curious complicated hinges. They vary very much in the tint 

 of the nacre inside. Some are orange-tinted, others pink or 

 purple, some without colour. The shells are worn very much 

 by the ladies of Sydney, as earrings and other ornaments, 

 being set in gold. 



The shell is especially interesting to the naturalist, because 

 it occurs fossil in secondar)'' deposits in Europe, and was long 

 supposed entirely a thing of the past, until discovered living 

 in Sydney Harbour. Moreover, with it occurs in the harbour 

 a most remarkable fish, the Port Jackson Shark {Cestracion 

 Philippi) which is also closely allied to fish, remains of which 

 are found in the deposits together with the Trigonias. 



It was believed for some time that the modern Trigonias 

 were very restricted in their distribution. A species occurs 

 however at Cape York, and Mr. S. C. J. W. van Musschen- 

 broek, Governor of Ternate in the Moluccas, told me that he 

 had obtained specimens of the genus from the coast of 

 Halmahera (Gilolo). A Port Jackson Shark is also found far 

 away from Australia, in the Japanese seas, and at intermediate 

 localities. 



