2 "ALBATEOSS" TROPICAL PACIFIC EXPEDITION. 



Looking into the narrow entrance of the deep Tai oa Bay, we can 

 trace the bedded Hnes of lava, following the general slope of the island, 

 and running across the numerous ridges, spurs, and diminutive peaks 

 which cover the steep slopes of the western side of the bay (PI. 2, 

 fig. 1).^ The volcanic strata, as cut by the valley, are seen to dip at 

 an angle of about 20° towards the sea, and the steep western slope is 

 gouged by deep channels forming secondary ridges or rather lamellae, 

 regular knife edges, along the whole western face of the valley. The 

 crests of the ridges and their faces are cut into endless peaks and 

 cones extending far up the continuation of the valley of Tai oa Bay. 



The high wall of stratified volcanic ash which extends between 

 Tai oa Bay and Tai-o-hae Bay is full of deep holes and caverns and pits 

 (PI. 2, fig. 2), and through it is cut Tai-o-hae Bay, where we anchored 

 during our stay at the Marquesas. The harbor is surrounded by the 

 sharp ridge running in a southerly direction from a peak rising to over 

 2100 feet to the north of the valley, forming a huge amphitheatre at 

 the back of the bay. The slopes of the ridge are bare, but the valleys 

 leading to the peaks are more or less well wooded. The entrance of 

 Ta'i-o-hae Bay is flanked on each side by two rocks called the Sentinels ; 

 they are remnants of the points which once extended farther out to sea 

 on both sides of the entrance to that harbor. 



The general account of Nukuhiva may serve for the other islands of 

 the group. They show the same prominent features, — a central ridge with 

 spurs extending towards the coast separating deep valleys ; their shores 

 either cut into deep bays or amphitheatres, or edged by high, steep vol- 

 canic cliffs formed by the disintegration of points once extending into 

 the sea, or by uniform lava slopes reaching from the central backbone. 

 The islands have their steepest faces on the easteni exposures attacked 

 by the southeast trades and the prevailing easterly winds which blow 

 from October to April. 



The Marquesas Archipelago^ consists of three fairly well defined 

 clusters, trending in a general direction from southeast to northwest 



1 A similar cliff is figured on A. Chart 1640 to tlie rear of Resolution Bay on Tauata Island, one 

 of the southern cluster of the group. 2 \_ Chart 1640. 



