20 TORTNTA. 



very wide, deepl}^ channeled, umbilical wall spirally ribbed ; 

 aperture round, nearly continuous, interior with alternating 

 bands of light and dark brown. Diam. 20 mill. 



Philippines ; Lord Hood Id. ; Sandivich Is. 

 T. cylindracsa, Hanley (in part); T. Ghemnitzn, Kien., are 

 synonyms. T. crenella, Linn., is possibly the same, but the 

 description is too vague. 



Yar. STRIGATA, Hanley. PI. 6, fig. 90. 



Periphery and the rib below it ornamented with white and 

 smoky-brown spots. 



T. FENESTRATA, Hiuds. PI. 6, figS. 100, 1. 



Shell depressed, slightly convex; whorls granular, longitudi- 

 nally striated, spirally sulcate and ribbed, the three ribs about 

 the periphery being strongest, suture channeled ; base rounded, 

 o-raniilar; umbilicus wide, margin many crenulated, umbilical 

 wall with fine spiral ribs; aperture round, nearly continuous. 



Diam. 10 mill. 



New Guinea. 



Hinds states that the type of this species was a dead shell, 



without color and, evidently, had been lying in the mud for 



some time. He thinks that perhaps the cancellation is somewhat 



more distinct than may be looked for in living specimens. 



T. viRGATA, Hinds. PI. 6. figs. 2, .3. 



Shell discoidal ; whorls granose, flat on top, rounded below, 



narrowly channeled at the suture, longitudinally striated, spirally 



sulcate and ribbed, the rib on the periphery and that below it 



being strongest; color pale-fulvous, with chocolate-red bands 



above and below the suture, on and below the periphery and 



near the umbilicus ; umbilicus moderate, with white crenulations, 



umbilical wall of a chocolate-red color, not ribbed ; aperture 



slightly angular. Diara. G mill. 



New Guinea. 



T, c^LATA, Hinds. PL 6, figs. 4, 5. 



Shell discoidal; whorls spirally -sulcate and tubercular near 

 the suture, radiately striated in the middle, periphery broad, 

 with two tubercular ribs ; color fuscous, shining ; base rounded 



