THE MOLLTJSCA OF TOREES STRAITS. 169 



particulars B. torresiense seems to differ : — first, the texture 

 is more delicate in Watson's species ; secondly, the tubercu- 

 lated gemmge, forming longitudinal ribs, are closer, and the in- 

 terstices simple, with no intervening lirse whatsoever. The whorls 

 are eleven in our species, as against eight, and the apical whorls 

 are similar, both in number and form, but the painting is different, 

 being flecked in one type with white. The dimensions are similar. 

 Three examples. 



147. PoTAMiDES (Ttmpanotonus) paltjstris, L. 



148. Potamides (Tsmpanotonus) retiferus, Sow. 

 Station 1, Thursday Island. 



149. Potamides (Terebralia) sulcatus. Born. 

 Station 13, Mer. 



MODULID^. 



150. Modulus obtusalis, Phil. . 



PLANASIDiB. 



151. Planaxis sulcatus, Born. 



" In interstices of coral shore-rock, the smaller being from 

 extreme high water-line, the larger a very little lower down " 

 {A. C. S.). 



Station 5, Boy don g Cays. 



152. Plaistaxis (Quoyia) decollatus, Quoy, 

 All of a dwarf form. 



TRICHOTROPIDIDiS, 



153. Separatista Blaijs^villeaka, Petit. 



A very large and perfect example, the dimensions of which 

 are : long. 11, diam. 17 mm,, thus much exceeding that of the 

 others recorded. It is a rare inhabitant of the Pacific islands, 

 and has not before been known to occur in the region embraced 

 by our paper. 



Plinders' Entrance, near Mer, 20 fathoms, Dec. 21st, 1888. 



Vermetid^. 



154. Vermetus (Siphonium) maximus, Sow. 

 Station 12, Mabuiag. 



