TAPJTAEI. 261 



kind of secondary lagoon, formed by the bulging out of the outer edge of the 

 reef flat, and running parallel to a slight projection of the outer shore line 

 of the land rim. One of the best examples of this is south of Butaritari 

 on the south face of Taritari (PI. 152, figs. 3, 4). 



Going west from Butaritari, towards the southwestern point, at the 

 extremity of the main street, we come upon a series of beach rock and 

 conglomerate ledges topped with steep sand beaches and enclosing shallow 

 lagoons. The outer rims of these are quite well defined by knolls of Nulli- 

 pores and Pocillipores, so that pools of from 50 to 75 yards in diameter are 

 formed extending from the base of the beach on the lagoon side. 



West of Butaritari, on the sea face, near the southwestern point, the 

 outer reef flat is edged by Nullipores ; on the flat are two or three islets 

 running parallel with the main beach of the island (PI. 224, fig. 4). At 

 the west point of Butaritari we found the extension of the Nullipore edge 

 which has formed the extensive flat running from the southwest point 

 northward, and immediately behind it a steep weathered coral shingle beach 

 covered with vegetation. From the beach a spit covered with only scant 

 vegetation cuts directly across the reef flat towards the shore of the 

 island, and forms a secondary lagoon, isolated, or only connected very 

 indefinitely with the main lagoon of Taritari. 



On the west side of the southwest point, near the village of Ukiaiinan, 

 we found that the southern extension of this wide reef flat becomes 

 gradually narrower as it reaches the village, and finally becomes a 

 part of the main shore of the island itself (PI. 154, fig. 4), widening out 

 again to a certain extent towards the southwest point. The Nullipore 

 boulders which have been thrown up on the shore (PL 154, fig. 4) consist 

 of large rounded masses ; they are mixed with round heads of Porites, 

 Maeandrina, and the like, and are gradually being pounded into coarse 

 black shingle. This, in its turn, is ground still finer, and forms the short 

 sand beaches alternating with beaches of Nullipore boulders. This coarse 

 black shingle beach resembles that of the west face of Maraki. 



A part of the southern area of Taritari is similar in structure to 

 that of the western side of Maraki. The secondary lagoons occupying the 

 great expanse of the southwest point of Taritari encroach upon its outer 



