CATALOGUE SHELLS. 



557 



lahri margine tenui, castaneo-maculatd ; long. | ; lat, -J J ; poll. 

 Habitat ? Mus, nost. 



51. LiTTORINA STRIATA. 



L. testa ovatO'ConicdfJuscd, striis elevaiis scabrd ; spird brevi ; an- 

 Jractu basalt tumido ; aperturd nigricante, basin versus strigd luteo' 

 albd ornatd; labri margine crenulato albo-fulmdo ; opercido nigro ; 

 long. ^ paulo plus ; lat. ^(;fere ; poll. 



Habitat in Mart Aflantico boreali (Port Praya). Mus. Brit., 

 nost. 



52. Margarita fasciata, n. s. 

 M. testa albidd, creberrime striatd, purpureo Jasciatd, aperturd ar- 

 gented ; long, -f^^ ; lat. -y^fere ; poll. 

 Habitat in Mari Pacijico. Mus. nost. 



Portions of the striated surface are elevated into belts, which 

 are of a purple colour. 



53, Margarita violacea. 

 M. testd sub-ovatd, violacea, spird brevi; anfractibus tumidis ; 



aperturd iridescente ; long. -^^ ; lat. -f^fere ; poll. 



Habitat ad f return Magellanicum. Mus. Brit., nost., Brod. 



Of this shell the Indians make their necklaces ; it is found adher- 

 ing to the leaves of the Fucus giganteus, and is the principal 

 food of the Steamer or Racehorse Duck (Micropterus Patachoni- 

 cus, nob. in Proceedings of the Zoological Society, December 

 1830, page 15). 



54. Margarita ccerulescens. 



M. testd sub-complanatd, cceruledi striatd, albido-lineatd, aperturd 

 iridescente; lat.\^Jere; long.\^ ; poll. 



Habitat ad f return Magellanicum (Cape Gregory). Mus. Brit., 

 nost., Brod. 



55. TURRITELLA TRICARINATA. 



T. testd turritd, anfractibus tricarinatis ; carinis nodulosis ; long. 

 If; lat. paulo minus ; poll. 



Habitat ad oras AmericcB meridionalis (Valparaiso). Mus. Brit., 

 nost., Brod. 



The Carinas are nodulous, or twisted like the strands of a rope ; 

 the twists of the upper carina are in the direction of a water-laid, 



