282 MOLLUSCA AND MOLLUSCOIDA 



tarium, E. A. Smith, was dredged at the profound 

 depth of 1803 fathoms. Amussium alcocki, E. A. | 

 Smith (Fig. 79), is a common species of the Lacca- I 

 dive Sea between 696 and 740 fathoms, and has also 

 been taken off the west coast of the Andamans in 

 561 fathoms. 



One of the most beautiful and most characteristic 

 bivalves of the Bay of Bengal on the verge of the 

 abyssal slope is Numla fultoni, E. A. Smith (Fig. 80), 

 the lustre of whose shell, when the outer protective 

 epidermis is removed, is like that of the choicest 

 pearls. In form and sculpture, as well as in brilliance, 

 this shell is one of those gems of purest ray serene, 

 which, in fine accord with the poet's prophetic im- 

 agination, the dark unfathomed caves of ocean bear. 



Another species that shares the habitat of Nucula 

 fultoni is Yoldia angtdata, Sowerby (Fig. 81), an 

 elegant little shell covered with a shiny olive-green 

 epidermis. 



Of the characteristic deep-water genus Cuspidaria, 

 whose shell is produced to form a long tube for the 

 protection of the siphons, five species have been dis- 

 covered by the Investigator, Cuspidaria macrorhynchus, 

 E. A. Smith (Fig. 82), from off the Laccadives in 

 636 fathoms, being the one that lives at the greatest 

 depth. 



Of the bivalve Molluscoida, only two species, both 



