412 
THE OCEAN WORLD. 
increase in size, movable bodies, sometimes of considerable bulk, suck 
as small flints, stems of plants, fragments of shells, all of which i* 
carries : hence its name of Mason. 
The Spurred Trochus, in the shell of which the turns of the spiral 
are studded with radiating spines, is represented by Trochus stella 
Fig. 21 7. Trochus agglutiaans (Lamarck) ; Fig. 218. Trochus Stella (Lamarck). 
Fhorus conchyliophoms (Born), 
(Fig. 218) and Trochus stellaris (Fig. 220) ; they are natives of the 
Australian seas. Trochus ivnperialis, vulgarly called the Royal Sp ut ' 
and Trochus or Rotella Zealandica (Fig. 219), the New Zealand Sp ur > 
the spiral turns of which are sculptured in descending furrows, a 11 '! 
studded with imbricated scales, which form a projecting edging round 
Fig. 219. Kotella Zealandica. Fig. 220. Trochus stellaris (Gmel.). 
the margin of the shell, and give it a radiating form. This species i g 
of a violet brown above and white below, and is still rare in collections- 
Rotella Zealandica , from the Indian Ocean, whose shell, represented h 1 
Fig. 219, presents the most lively colours, forms one of a genus b) 
no means numerous in species. 
Beside the genus Trochus naturalists range a pretty marine sbelh 
called the Sun-dial (Solarium), recognised by its profound umbili cVlS ’ 
wide and funnel-shaped, in the interior of which maybe seen the lb fclt 
crenated teeth which follow the edge of every turn of the spiral np 
