PLEUROTOMA. 165 
the keel-rib, and somewhat larger size and proportionally longer 
canal will distinguish it from the last species. 
P. auBIna, Lamarck. PI. 2, fig. 14. 
Keel-rib flattened, bearing a row of equidistant, somewhat 
quadrangular brown spots, the rest of the surface very minutely 
and numerously punctate with brown. L. 58, diam. 15 mill. 
Moluccas. 
The conspicuous painting on the slit-band, contrasted with 
the very minute sprinkling of brown dots elsewhere, is the 
distinguishing characteristic of this species. 
P. gRacittima, Weinkauff. PI. 2, fig. 15. 
Shell spirally ribbed, the second rib from the sutures crenu- 
lated, the third prominent; white, sparsely maculated with chest- 
nut. L. 36, diam. 9 mill. 
Habitat unknown. 
Distinguished by its narrow, graceful form, and crenulation. 
P. MARMORATA, Lamarck. PI. 2, figs. 16, 16a, 17. 
Shell rather sharply carinate on the shoulder, encircled by 
narrow small, sharp ribs and intermediate raised lines; white, 
usually thickly maculated in a longitudinal manner with chestnut- 
brown, sometimes minutely punctate with chestnut. 
L. 75, diam. 21 mill. 
Red Sea, Malacca, Japan, Australia, Polynesia. 
The usual appearance of this species is represented by fig. 16 ; 
occasionally it is spotted, and sometimes it is entirely devoid 
of coloring. IL. hastula, Reeve (fig. 17),is the young of this 
species. 
P. PEasEANA, Dunker. PI. 2, fig. 18. 
Shell carinate, with a pair of prominent ribs at the suture and 
other less prominent ribs and raised lines throughout ; yellowish, 
flammulate with brown. LL. 25, diam. 7 mill. 
Indian Ocean. 
A young shell, which may possibly prove to be identical with 
P. Garnonsti, Reeve. 
P. uneDo, Valenciennes. PI. 3, fig. 20. 
Shell angularly turreted, with concavely sloping shoulders 
defined by duplicate granular ribs, forming the angle; every- 
