124 THE VOYAGE OF H.M.S. CHALLENGER. 



of lithological constitution as we have already had occasion to notice at other parts of 

 the island. A little farther along the coast to the west is Irish Bay ; it receives the 

 river descending from the Naumann glacier, which stops at a distance of five nautical 

 miles from the end of the bay. At the foot of the glacier doleritic basalts are found 

 in situ ; these are sometimes amygdaloidal, and marked with glacial striae ; a trachytic 

 rock enclosed in the basalt may also be observed. 



Foundry Bay succeeds that last mentioned. It is a fjord barely two-thirds of a mile 

 wide at the entrance, with Gazelle Basin situated in its western angle, and Schonwetter 

 Harbour at its eastern extremity. The rocks from the shores of this bay are doleritic 

 basalts, with olivine and geodes of chabasite, quartz, and agate. Amygdaloidal dolerites, 

 containing fine geodes of heulandite, quartz, and chalcedony, are found at Schonwetter 

 Harbour. There are also fine-grained basalts, and tufas of the same lithological nature. 



Continuing towards the east we reach the most thoroughly known peninsula in 

 Kerguelen, that named Observations Halbinsel by the German explorers, and made the 

 object of a detailed topographical survey by Captain von Schleinitz, who commanded 

 the " Gazelle." ' Dr. Th. Studer, naturalist to the German expedition, published a 

 memoir full of facts regarding this part of the island. He remained for more than three 

 months in the neighbourhood of Betsy Cove, and his work comprises a most complete 

 set of observations on the topography and geological conditions. The latter are treated 

 with special detail, comprehending the study of the basaltic and trachytic eruptive 

 masses, the deposits formed by running water, glacial phenomena, erosion by sea and 

 rivers, and recent oscillations of the ground. It is impossible to give an abstract of 

 this work here, the reader must therefore refer to the original paper. We may, however, 

 state the principal features of the physical geography of this peninsula, and summarise 

 the chief varieties of rocks collected by Dr. Studer and determined by Professor Both. 



The Strauch hills, attaining a height of 1150 feet, and Castle Mount, with an eleva- 

 tion of 1550 feet, stretch towards the west, and farther in the same direction lies the 

 valley of Cascade Biver, one tributary of which flows from Lake Margot, another having 

 its source a little farther north. Mount Crozier rises to 3000 feet at the south of Lake 

 Margot. The peninsula on the north and east is simply a plain about 30 feet above sea 

 level, covered with rolled pebbles, and diversified by lakes and marshes. On this plain, 

 to the south of Accessible Bay, are situated the Tafelberg (275 feet), and three isolated 

 summits — Mount Campbell (about 460 feet) lying farthest north, Mount Peeper (650 

 feet) next it, and to the south of these the crater-shaped Mount Bungary. 



In what follows we shall give special prominence to the observations of the British 

 naturalists, which -only refer to the special point of Betsy Cove, where the Challenger 



1 See Annakn der Hydrographie, Bd. ii. No. 19, p. 220, 1875. 



