OF MOLLUSCA. 



145 



15. Imperator. 



Operculum thin, flat, rather thinner on edge. Shell : whorls 

 keeled, with hollow compressed spines. 



1. I. Solaris. 



16. Cookia. 



Operculum ovate, with a slight tubercle over the axis, and a single 

 subcentral arched rib. Shell top-shaped, rugose, imperforated, con- 

 cave over the axis. 



1. C. nobilis, t. 40. f. 2. 



17. BOLMA. 



Operculum ovate, suborbicular, convex, with a subcentral tubercle 

 over the axis, and a broad submarginal spiral rib . Shell top-shaped, 

 rugose ; aperture circular. 



1. B. rugosa, t. 43. f. 6, t. 107. f. 1, 5, t. 108. f. 5. 



c. Eutropiana. Body of animal, aperture and operculum ovate. 



18. Eutropia. 



Shell ovate ; spire conical ; whorls smooth, polished ; aperture 

 oval ; pillar smooth ; outer lip thin, simple. Operculum ovate, ex- 

 ternally convex, smooth. 



1. E. australis, t. 41. f. 1, 2. 



2. E. pulla. Phasianella p., Forbes fy Hanley, B. M. t. D.D. f. 5, 



frontal lobes slender. 



Central tooth of Eutropia pulla transversely ovate, produced in the 

 middle at the base ; cutting part not recurved, entire ; lateral teeth 



Fig. 79. — Teeth of Eutropia pulla. 



five on each side, oblique, the four inner imbricated; cutting- 

 edge recurved with three to four points, in the fourth at the side, 

 and furnished with a process winged outwardly, in the third and 

 fourth obsolete, fifth sublinear, clavate. Lateral series of teeth on 



