On a New Mineral from M'lvor. 17 



Trigonia and Terebratula are still in existence, which fed 

 the fishes of the Oolitic era. From the locality from whence 

 the present specimens were obtained I should not conceive 

 they are sought after by the Port Jackson Shark in such 

 shallow water, and am not aware (other than the fact that 

 they are discovered in a fossil state in the same localities) 

 that they are, or were, consumed as food by the fish now 

 under consideration. They have a curious kind of internal 

 skeleton, as it may be termed, consisting of a flattened calca- 

 reous loop, with other pieces diverging from it, which are con- 

 sidered to be supports to the animal's body. There are sixteen 

 recent, and numerous fossil species. 



The oldest fossil Mammalia are in the Oolite, also forming 

 peculiar genera, belonging to the insectivorous Marsupialia, 

 such as live now in Australia only. 



Art. V. — On a New Mineral from M'lvor. By R. Brough 

 Smyth, Esq., C.E., F.G-.S. 



[Read before the Institute, 4th March, 1857.] 



The mineral described in the following analysis was for- 

 warded to me by Philip Chauncey, Esq., District Surveyor, 

 Heathcote. It occurs commonly in the quartz veins in small 

 quantities, and is believed by the diggers to be Molybdenum. 

 As my duties at present prevent my Mineralogical studies, 

 I handed the specimens to George Ulrich, Esq., who has 

 prepared the analysis which I now submit to the members of 

 the Philosophical Institute.* 



" The mineral is of a steel-grey colour, with metallic lustre, 

 opaque, brittle; the fracture isconchoidal; the streak-powder 

 dark-grey, or black; hardness 2*5 — 3; spec. grav. (?) 



" Before the blowpipe, on charcoal, this ore smelts very 

 easily to a metallic globule, with a sort of boiling motion, 

 emitting at the same time dense white fumes, with a weak 

 smell of sulphurous acid. Close to the mineral the charcoal 

 bears a deep yellow crust, which gradually changes into white ; 

 then comes a small uncoloured ring, and again a small blueish 



* Mr. Ulrich was not aware of my intention to publish these results until 

 after his analysis was published, or his examination would have been more 

 complete.— R. B. S..,, 11th July, 1857. 

 VOL. II. C 



