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FAMILY FUSID^. 

 G-ENUS Fusus. 



SYNOPSIS OF SPECIES. 



I. Periphery carinated,* bearing hollow spines or foliations. 

 Keel with foliar extensions. 1. F.foliaceus. 



Keel with spinous extensions. 

 {a). No spines in front of keel. 



Posterior slope of whorl lirate. 



Basal lirae spinous ; posterior slope concave. 



2. F. acanthostephes. 

 Basal lirae without spines ; posterior slope 



convex. 



3. F. craspedotus. 

 Posterior slope without lirae. 



Basal lir^e without spines. 



4. F. spiniferus. 

 (5). Two rows of spines in front of keel. 



One row of spines behind keel. 



5. F. cocJileatus, 

 Two rows of spines behind keel. 



6. F. se?iticosus.'^ 

 The species of this group are obviously congeneric with 



F. pagoda, Lesson, which Professor v. Martens has recently at- 

 tached to a new sub-genus of Pleurotoma, named Columbarium, 

 'On account of peculiarities of the radula ; but on conchological 

 .grounds it will be convenient to include them under Fusus. 

 II. Periphery (of last whorl at least) angulated or shouldered ; 

 whorls ribbed or tuberculated. 



"Whorls tabulated, crenate-dentate on the keel. 



7. F. d id y Otis. 

 Whorls equally sloping from the angulation. 



Lirae on penultimate whorl. 



Ten, stout, equal. 8. F. Johnstoni. 



Twenty, slender, unequal. 



9. F. simulans. 



Seven, slender, subequal. 



10. F. sculptilis. 

 Whorls angulated over anterior suture. 



Periphery with keel-like ridges. 



7. F. dicfyotis, var. 

 Periphery with blunt nodulations. 



11. F. incompositus. 

 Periphery with cuneiform, acute, tubercles. 



* In most examples of F. senticosus, the whorls are quadrately rouncled 

 and only feebly carinated. 



