324 EEV. E. BOOG WATgOlS' ON THE 



MoLLTJSCA or H.M.S. ' Challenger' Expedition. — Part XII. 

 By the Eev. Egbert Boog Watson, B.A., F.E.S.E., E.L.S. 



[Published by pei'misslon of the Lords Commissioners of the Treasury.] 

 [Bead December 15, 1881.] 



Para. CancellariidjE. 



VoLUTIDiE. 



Fasciolariid^. 



Fam. CoLUMBELLID^. 



Olivid^. 



The Volutes are the most interesting of the ' Challenger ' 

 Mollusca. In particular I may mention Volutilithes alyssicola, 

 Adams and Eeeve, known hitherto only in the form of a single, 

 very young shell, got by the ' Samarang ' off the Cape of Grood Hope 

 in 132 fathoms. Of this the ' Challenger ' got three specimens 

 from the same locality, presenting in their full-grown form fea- 

 tures of so much importance as to require a complete revision of 

 the species, especially in its relations to the Miocene forms of the 

 genus. 



Even more interesting is the new Volute form of Provocator 

 from Kerguelen Island, 105 fms., presentiug the apex of an 

 Aiicillaria, the suture of a JBullia, the pillar-plaits of a Valuta, 

 and the lip-sinus of a Pleurotoma. 



The gem of the whole collection, however, is the very remark- 

 able and beautiful TVyvillea alabastrina, from 1600 fms., or nearly 

 10,000 feet, in the Antarctic Sea, which very much exceeds in 

 size any thing yet obtained from the great ocean-depths. The 

 specimen having been secured in life. Professor Huxley has under- 

 taken the minute dissection and description of the animal, which 

 was preserved in spirit. 



There are many other forms of interest embraced in this part 

 of my Eeport which I need not enumerate here. I may add, how- 

 ever, in this place that the exigencies of the official Eeport and 

 the embarrassments of my own professional work compel me to 

 deal more summarily with the material entrusted to me than I 

 have hitherto thought it right to do. This will explain the omis- 

 sion of many groups which, embracing only very small or badly 

 preserved specimens, require a greater amount of minute study 

 than time allows me now to give. These may possibly be over- 

 taken afterwards, but must be nedected now. 



