158 Proceedings of the Royal Society of Victoria. 



eastern portion of the neck. Whether or not it extends to the 

 mai-gin of the neck could not be determined, as sand, mud and 

 sea-weed obscure the surface. 



The main portion of the neck consists of agglomerate, formed 

 of a heterogeneous mixture of blocks and fragments of decomposed 

 basalt, diflerent in character from that present in a hard state ; 

 Jurassic strata, such as sandstones, shales and mudstones ; tuff, 

 lapilli, and a material that looks like a volcanic mud. The 

 included fragments of Jurassic strata are in some cases consider- 

 ably indurated, but generally show little evidence of alteration. 

 In the northern portion this material is of finer texture, and 

 shows rude prismatic and spheroidal structure. Along the 

 southern edge for several yards in two separate streaks, lying 

 between the laminated basalt and the containing sandstones, 

 there occurs vertically laminated tuff, varying from a quarter of 

 an inch to 9 inches in thickness. The included blocks of Jurassic 

 sandstones, mudstones and shales range in size up to 6 feet by 4 

 feet, those of decomposed basalt being much smaller. 



The northern portion of the neck runs out into a sharp point 

 where the contiguous fine argillaceous sandstone shows distinct 

 curved structure on a small scale, the jointing being about vertical, 

 and following the curve of the adjacent part of the periphery. 



The sandstone is slightly hardened, but otherwise not altered. 



The Jurassics here form portion of a dome which extends along 

 the beach in a north-easterly direction. The neck has been 

 formed in the north-western portion of this dome. The contigu- 

 ous strata dip generally N.W. at about 28 deg. on the north- 

 western edge, and curve a little to the N. along the northern 

 edge. Numerous faults may be seen, but their characteristics 

 cannot be definitely ascertained owing to the overlying sand, 

 mud and water. They will be briefly described under a separate 

 head. 



Volcanic Neck, 2. 



This neck is a much larger one than Neck 1, in fact it is the 

 largest of the group. In character it ditters greatly from Neck 1. 

 Almost its whole visible portion consists of an agglomerate. 



It has a visible length from north to south of about 12 chains, 

 and a visible breadth of about 8 chains. It appeal's both at and 



