160 Proceedings of the Royal Society of Victoria. 



with a reddish-brown surface, but forms a fairly dark soil. A 

 fair-sized patch of similar rock occurs on the beach under high- 

 water mark. It wears into ragged edges. 



A very vesicular basalt, of fine texture and brownish-grey 

 colour, occurs as a block among agglomerate in the cliff. The 

 vesicles are apparently caused by the decomposition and removal 

 of the carbonate of lime from amygdules of calcite. There is 

 also a little lapillaceous tuff, consisting for the most part of 

 fi'agments the size of peas, and showing distinct bedding. It 

 has a considerable amount of greenish-grey volcanic mud, and 

 blunted pieces of the fine decomposed basalt up to the size of 

 pigeons' eggs. A pretty rock of light drab-grey colour, grading 

 to yellow at the surface, a decomposed basalt, occurs as an 

 inclusion in dense basalt on the beach, west of the private jetty 

 built by Mr. Cuttriss. It is composed of multitudes of thin, 

 narrow, transparent, coloui^less crystals up to one-sixteenth of an 

 inch in length, set in a matrix of yellowish clay, probably decom- 

 posed felspar. Another kind of decomposed basalt of light grey 

 and yellow colours occurs at this spot. It is an intimate mixture 

 of minute crystals with occasional vesicles of clay. It resembles 

 very much the included pieces of decomposed basalt in the agglo- 

 merate of Neck 1. 



There are two other rocks found in this dense basalt which are 

 of interest. One is of dense, hard, dark blue amorphous material 

 with small amygdules of yellowish-brown ferruginous powder. 

 It is a rock with a peculiar appearance, and gives one the 

 impression of being a form of a mud lava or basaltic mud. It 

 also contains small patches of olivine, partially altered about the 

 edges into an opaque white substance. Small lenticles of this 

 hard amorphous material also occur in parts of the agglomerate 

 in the cliff, and they would probably be turned by decomposition 

 into the brownish-grey mud comprising the lenticles in the 

 decomposed agglomerate on the beach. 



The other rock is a light and medium grey compact mud, with 

 numerous very small amygdules of a brown glassy )nineral. The 

 rock weathers a light grey, and is a good deal like the last 

 mentioned. They both appear to have been formed from the 

 solidification of pasty material of basaltic origin, perhaps crushed 

 or ground-up basalt mixed with liquids, and to have gained their 



