Geological Society of London. 569 



tion from those which Avere capable both of persistence and modifi- 

 cation ; and these again from the inadaptive types which have died 

 out. The aberrant and highly specialized parasitic types appear last 

 in time, and mark the culminating point of the Crustacea when con- 

 ditions jDrevailed more highly favourable to the class than at any 

 earlier period. 



GrffiOLOGiCAL SociETT OF LoNDON. — November 6, 1872. — Prof. 

 Eamsay, F.E.S., V.P., in the Chair. — The following communications 

 were read: — 1. "A Eeport by F. T. G-regory, Esq., Mining Land 

 Commissioner in Queensland, on the recent discoveries of Tin-ore 

 in that Colony." Communicated by the Right Hon. the Earl of 

 Kimberley, Secretary of State for the Colonies. 



According to this report, the district in Queensland in which tin- 

 ore has been discovered is situated about the head-waters of the 

 Severn river and its tributaries, comprising an area of about 550 

 square miles. The district is described as an elevated granitic table- 

 land intersected by ranges of abrupt hills, some attaining an eleva- 

 tion of about 3,000 feet above the sea. The richest deposits are 

 found in the beds of the streams and in alluvial flats on their banks, 

 the payable ground varying from a few yards to five chains in 

 extent. The aggregate length of these alluvial bands is estimated 

 at about 170 miles, the average yield per linear chain of the stream- 

 beds at about ten tons of ore (cassiterite). 



Numerous small stanniferous lodes have been discovered, but only 

 two of much importance, namely, one near Ballandean Head Station on 

 the Severn ; and another in a reef of red granite rising in the midst 

 of metamorphic slates and sandstones at a distance of about six 

 miles. The lodes run in parallel lines bearing about N. 50° E. ; 

 and one of them can be traced for a distance of nine or ten miles. 

 The ore, according to Mr. Gregory and Mr. D'Oyly Aplin, is always 

 associated with red granite, i.e. "the felspar a pink or red orthoclase, 

 and the mica generally black ; but when crystals of tin-ore are found 

 in situ, the mica is white." The crystals of tin-ore are generally 

 found in and along the margins of quartz threads or veins in bands 

 of loosely aggregated granitoid rock, but are sometimes imbedded 

 in the micaceous portions. The report concludes with some state- 

 ments as to the present condition and prospects of the district as 

 regards its population. 



2. " Observations on some of the recent Tin-ore Discoveries in 

 New England, New South Wales." By G. H. F. Ulrich, Esq., F.G.S. 



The district referred to by the author is in the most northern part 

 of the colony of New South Wales, almost immediately adjoining 

 the tin-region of Queensland described in the preceding report. It 

 forms a hilly elevated plateau, having Ben Lomond for its highest 

 point, nearly 4,000 feet above the sea-level. The predominant rocks 

 are granite and basalt, inclosing subordinate areas composed of 

 metamoi'phic slates and sandstones ; the basalt has generally broken 

 through the highest crests and j)oints of the ranges, and spread in 

 extensive streams over the country at the foot. 



