414 THK GEOLOGY OF THE NEW HEBRIDES, 



cinder}' appearance and acquiring an increased abundance of 

 corals, pass upwards into a solid coral rock. 



The following forms have been identified as occurring in this 

 bed:- 



Pelecypoda—?,, 6, 7, 9, 11, 12, 13, 23, 26, 27, 30. 



Gastropoda— b, 8, 12, 17, 19, 24, 26, 34, 35, 38, 39, 43. 



Echinoderms — 1, 2, 4. 



Cora/s — S, 15. 



In the lower portions of the overlying reef the following 

 fossils were collected : — 



Pelecypoda — 4 . 



Corals— \0, 14. 



Pau Uma is a rugged island situated between Epi and Ambrym. 

 It has a length of 5 miles, breadth 2 miles, and area 9 sq.miles. 

 Running in a N. and S. direction down the centre of the island 

 is a chain of mountains, apparently volcanic, attaining a height 

 of 1825 ft. No reliable data relating to the geology of this island 

 are available. 



LoPEVi is a remarkable volcano situated 16 miles S.E. of the 

 crater of Ambrym. It is only 3 miles in diameter at the base, 

 but it towers upwards in a perfect cone to the crater, about a 

 quarter of a mile in diameter, situated at an elevation of 4755 ft. 

 Although not always active, Lopevi has several times since 

 European occupation poured forth lava, which, welling over the 

 crater, has descended from that immense height in brilliant 

 streams down into the sea. 



Ambrym is triangular in general outline, with a greatest length 

 of 21 miles, and an area of 160 sq.miles. The island is a remnant 

 of an immense volcano,* with an extinct crater six miles in 

 diameter; at the present time, however, activity is restricted to 

 minor vents situated in two daughter-cones. f The floor of the 



• For further details of volcanic phenomena, see Section 2 (p. 427). 

 t The term daughter-cone is here used to signify a younger development 

 inside an older crater. 



