GENERA AND SPECIES. 



137 



Rissoa. (RISSOIDJE.) Plate xxiv. 

 Outer lip plain- 

 Shell smooth 



white, -with 4 rows of brown spots on 

 body whorl ; whorls 4. 



cream, with 2 brown bands on body whorl, 

 whorls 4. 



pale yellow, whorls 5, finely striated. 

 white, whorls 6, finely striated and lustrous. 

 white, smooth and dull ; whorls 6. 

 white, with a row of brown streaks, whorls 6. 



white, with 2 brown bands on body whorl, 

 whorls 6 or 7. 



Outer lip thickened and reflected 

 Shell ribbed lengthways 



409. zetlandica, 



410. costata, 



in. outer lip toothed, 16 ribs on body whorl. 

 in. outer lip sinuated, 9 ribs on body whorl. 



Outer lip ribbed 

 Shell cancellated 



407. punctura, 



punctured and prickly at angles of inter- 

 section, colour white, often spotted with 

 brown. 



outer lip toothed, whorls angulated. 



shell turreted, spire pointed, suture shallow. 



shell turreted, spire blunt and slightly 

 truncated, suture deep and channelled. 



cancellations coarse, 16 ribs on body whorl, 

 suture broadly excavated. 



cancellations minute, longitudinal striae as 

 prominent as transverse striae; shell conical, 

 spire acute. 



longitudinal striae faintly marked, shell 

 oblong, spire acute. 



sne H oval . s P ire abruptly pointed, suture 

 narrow and distinct, 20 ribs on body whorl. 



shell oval, spire short and abrupt, suture 

 deep and channelled, whorls 5. 



Outer lip ribbed- 



Shell ribbed and spirally striated 



416. costulata, ^ in. striae punctured, suture deep, whorls 8, 



colour buff, with brown and lilac. 



413. albeila, f in. spire with a sharp point, suture very deep. 



417. striata, in. spire with a blunt point, suture deep. 

 415. violacea, in. spiral striae punctured, suture narrow. 



K 



404. 



401. 



reticulate, 



lactea, 



408. abyssicola, 



\ in. 



in 



