﻿MR. F. W. O. RYMER JONES ON SOME 



LAGEN.E 



69 



Fig. 59 a. The same : sectional outline of^ x 300 diam . 

 Fiff. 60. L. vulgaris, Williamson, var. bicamerata. Nov. : 



foramina 



40 



Fig 



two-chambered shell, the lower end of which is 



delicate 



diam 



Fig. 62. The same : two-chambered shell, the upper chamber of which is ornamented with costse, which are 



. also visible at the extreme base of the primordial chamber, x 140 diam. 



Note. 



4 



The temperature of 47° F. at 1080 fathoms may seem somewhat higher than might he 

 expected at that depth ; but this portion of the ocean is so enclosed by shoals and reefs, 

 that the deeper and colder waters of the more open seas are in a groat measure cut off ; 

 and consequently, though its depth is considerable, its temperature is much higlicr than 

 at equal depths in the outer ocean. A similar contrast is observable between the tem- 

 perature of the Sulu Sea and that of the China Sea, as shown by observations made by 

 Commander Chimmo, the temperature in the former being as high as 50° F. at the depth 



of 1778 fathoms. 

 The thermometers used for these soundings were " Johnson's patent metallic spring," 



placed in stout perforated gutta-percha cases. 



