CHAPTER XIX 



OF THE DEEP-SEA MOLLUSCA AND MOLLUSCOIDA OF 

 THE INDIAN OCEAN 



Between the depths of loo and 2000 fathoms a great 

 many species of Mollusca have been dredged by the 

 Investigator, and most of them have been described by 

 Mr E. A. Smith, in various papers published in the 

 Annals and Magazme of Natural History, from the 

 year 1894. They belong to the following groups : — 



Gastropoda, 68 species. 



Scaphopoda, 6 „ 



Cephalopoda, 10 (described by Mr E. S. Goodrich). 



LameUibranchiata, 44 



Of the Gastropods, the dweller in the remotest 

 depths is Pontiothauma 7nirabile, E. A. Smith, a large 

 blind species with a colourless shell, surprisingly like 

 that of the common whelk of northern seas : a unique 

 specimen of this large species, which has neither eyes 

 nor radula, was dredged in the Laccadive Sea at a 

 depth of 1250 fathoms, on a bottom of blue mud, the 

 temperature being 36° Fahr. ; its shell was nearly 5i 

 inches long. 



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