10 
n. T. FERRAR. 
successive lava-flows laid horizontally one upon another. These rocks are similar in 
character to the lavas with lenticular felspars of Cape Royds, and are also related to 
the rocks of the neighbouring Dellbridge Islands, to be considered later. 
Mount Bird is a flattened dome over 3000 feet high and, like Mount Terra Nova, 
which attains a height of about 7000 feet, is an undenuded volcanic cone. No 
specimens have been obtained from either of these mountains. 
Mount Terror (Plate I) is a quiescent volcano 10,750 feet high. It forms the 
eastern part of Ross Island, and, though not quite so high as Mount Erebus, 
covers almost, as great an area. Its base is circular and has a diameter of perhaps 
20 miles ; its surface is almost completely snow-covered. On the south side the 
covering is so thick that no parasitic vents, if present, could be distinguished. On 
the north side, especially above Cape Crozier, is the largest area of rock-exposure, 
and here all eminences which have been examined were of the nature of subsidiary 
surface lava-flows. Some 
of these are quite con- 
spicuous, and from them 
many specimens have been 
collected. 
The ‘Southern 
Cross ’ Expedition * ob- 
tained hornblende-basalts 
from a bare rock-cliff 
10 miles or so to the 
west of Cape Crozier, and 
from the red and yellow 
“blazes” that occur in 
this cliff it would seem 
that basalt-agglomerate is also present. From the cones on the east side of the 
mountain above the Great Ice Barrier of Ross, Dr. Wilson collected basalt-scoriae 
(824) and limburgite (825) and proved the cones to be due to subsidiary eruptions. 
From the bare rock-cliffs (Crozier Cliffs), against which the ice-sheet abuts, Dr. Wilson 
also collected rock, in situ. His specimens are of two kinds: (1) columnar basalt (830 
and 848), which forms the mass of the cliffs and reaches a height of 800 feet above 
sea-level; and (2) a yellow trachytic rock (831), occurring in irregular lenticles in 
the mass of the cliff. At one spot a rough stratification was observed, and it is 
possible that stratified tuffs are there developed. 
From a locality he termed the V- Cliffs Hogsback, Mr. Hodgson collected 
specimens of coarse yellow tuff (783), red vesicular basalt (778) and a basaltic bomb 
(77G). This locality is on the south-east side of Mount Terror, 20 miles south of Cape 
Crozier and 30 from the ship. It is one of two exposures which have been found on 
* Prior, Rep. ‘ Southern Cross’ Collections (British Museum), 1902, p. 322. 
Fig. 5. — Cape Crozier and Mount Terror. 
