VOL V ARIA. 51 



Notwithstanding the differences above indicated by extreme 

 specimens, the shells appear to grade into one another and to 

 approach very closely the old M. avena of Valenciennes, of 

 which indeed this may be but an abyssal race ; but of the latter 

 I have no typical specimens, and it is described as having color- 

 bands. In view of the great number of closely allied forms of 

 this group, without such specimens it would be rash to consolidate. 



Another form with the spire almost lost (from Yucatan Strait, 

 640 fms., and Station 2, 805 fms.), of a yellowish white tinge, 

 strongly resembles d'Orbigny's M. triplicala, which I take to 

 have been founded on an abnormal specimen, and might be 

 thought a pale race of Volvarina varia, but I am not at all sure 

 that it is not an extreme form of the preceding. 



I quote Mr. Ball's description of the above varieties in full, as 

 they are unfigured, and are deep-sea forms; they are doubtless 

 varieties only, as suspected by Mr. Dall. 



M. PATAGONICA, Martens. PI. 13, fig. 40. 



White, with two wide light rosy bands ; columella with four 

 plications, the lower the strongest. Length, 18 mill. 



East Coast of Patagonia 60 fathoms. 



M. PHILIPPINARUM, Redfield. PI. 13, tig. 6; PI. 2, fig. 9. 



Yellowish white, with three rather broad darker bands ; 

 columella four-plaited. Length, -5-'65 inch. 



Philippines. 



M. EXILIS, Gmelin. PL 13, tigs. 7,9, 10,11,96,97; PI. 12, fig. 59. 



Yellowish white, without bands, or three-banded with light 

 chestnut. Length, 10 mill. 



W. Africa, Mogadore to Senegal; West Indies. 



A more ventricose, shorter species than some of those which 

 precede it. It is the M. triticea of Lamarck (fig. 7), M. monilis 

 of Wood, not Linn. M. epigrus, Reeve (fig. 9), is supposed by 

 Mr. Redfield to be the young of this species. M. tribalteata, 

 Reeve (fig. 11), and M.fusca, Sowb, (figs. 96, 97) a West Indian 

 shell, are synonyms. I am inclined to place here, as a not fully 

 grown shell, M. Benguelensis, Jouss. (PI. 12, fig. 59 ; PI. 13, fig. 

 10), from Benguela. M. Jousseaumi, Rochbrune, from the Cape 

 Verd Islands, is also a synonym. 



