130 



GENERA AND SPECIES. 



Whorls less than 10 

 Spire turreted 



495- excavata, \ in. whorls 6, white, prominent spiral ridges and 



raised longitudinal ribs, outer lip with four 

 angular points, pillar with tooth. 



496. scalaris, in. whorls 8, light yellow, ribs more prominent 



than striae, pillar without tooth. 



494. fenestratj, fy in. whorls 8 to 9, white, body whorl with 20 



longitudinal ribs crossed by 3 spiral ridges, 

 pillar without tooth. 



Spire not turreted 

 Pillar without tooth 



489. clathrata, % in. whorls 6 or 7, 3 rows of ribs on body whorl. 



490. indistincta, ^ in. whorls 7 or 8, 6 to 8 rows of ribs on body 



whorl. 



Pillar with tooth 



493. eximia, ^- r in. mouth oval, whorls 4 or 5, ribs on body 



whorl 15, crossed by 3. 



492. spirahs, J in. mouth oblong, whorls 5 or 6, ribbed length- 



ways above and spirally beneath. 



491. interstincta, ^ in. mouth oval, whorls 5 or 6, over 18 ribs on 



body whorl. 



Pillar curved 

 Shell turreted 



488. decussata, 



in. whorls 4, ribbed and spirally striated. 



470 truncatula, 



Whorls 5 or more 

 Whorls flat 



whorls 6 or 7, no prominent ridge bordering 

 suture, suture channelled. 



Whorls convex 



485. oUiqua, 



486. warreni, 



481. tiirrita, 

 483. insculpta, 



482. plicata, 



whorls 5, swollen, basal striae faint, umbili- 

 cus none or indistinct, mouth pear-shaped. 



whorls 5, swollen, basal striae distinct, 

 umbilicus small but well marked, mouth 

 pear-shaped. 



whorls 5 or 6, mouth square. 



whorls 6, convex, spirally striated, suture 

 narrow, mouth irregularly oblong. 



whorls 5 or 6, shell thin and slender, spire 

 long and finely tapering, mouth oval and 

 angulated above. 



