424 NOTES AND EXHIBITS. 



The rock is composed of large fraguients of olivine, from one 

 to four inchss iu diameter, and large crystals of augite from 

 half inch to one and a half inches in diameter, set in a ground- 

 mass of basalt. Both the fragments of olivine and the crystals of 

 augite show evidence of having undergone much corrosion, especially 

 the augite, which although occurring in well-formed crystals have 

 had all their angles rounded off by fusion, so that many of them 

 have the a[)pearance of small oval pebbles. This fact is of great 

 interest (1) as pointing to the fact that the olivine and augite havi^ 

 not crystallised out in the rock upon cooling subsequent to its 

 intrusion, but must have crystallised and partly solidified at a 

 considerable depth, and have been transported by the basalt to 

 their present position in the course of its eruption ; (2) as regards 

 the temperature of the basalt it is evident that at some period ci- 

 point of the eruption it was sufficiently high to fuse olivine and 

 augite. The mode of occurrence of this remarkable rock is not 

 yet known, but it is presumed by Mr. Wilkinson to occur as an 

 intrusive boss. 



Also, a specimen forwarded for determination to Mr. C. S. 

 Wilkinson of the Department of Mines from the Canoblas, neai- 

 Orange, which proves to be a very interesting variety of rock 

 belonging to the Gabbro group. The rock is crystalline, granular 

 in structure, and consists essentially of a diallage-like mineral, 

 some variety of felspar (?), and a little magnetite. The precise 

 species of this rock has not yet been determined, but it may be 

 provisionally classed amongst the Gabbro group. This is, as far 

 as Mr. David is aware, the first notice of the occurrence of this 

 rock in New South Wales. 



Mr. A. Sidney Olliff exhibited (1) Palaeotoma styphelana, Meyr., 

 a lepidopterous insect (fam. Tortricidai) which he had bred from 

 the 2:all of a new species of Coccus belonging to the family 

 Brachyscelidai. The species appeared to be an inquiline and not 

 the maker of the gall, as was supposed by the original describer 

 "of the species. The identity of the moth with P. styphelana was. 



