TUUIiO. 1 9 J 



confounding with any other. It is distingiiiyhed by the close 

 succession of concentric laminsG crossing the somewhat dis- 

 tant ribs. Mr. Crouch has kindly lent me a specimen with 

 an authentic operculum, unfortunately too late for tigurino-. 

 The operculum is no less remarkable and beautiful than the 

 shell — convex with a deep umbilicus near the centre, lio-ht 

 brown with dark brown concen'-ric bands, exquisitely orna- 

 mented with small erect clo?e-set scales ; left side thick, 

 otherwise bordered by a flatteneu keel. — Hab. Australian 

 coasts. The operculated specimen, Port Walcot, North 

 Australia (Capt. Beckett). 



15. SPINOSUS, pi. iii. f. 1 7, 18 ; also f. 32, 63, 77, Chemnitz, 

 Conch. Cab. vol. v. p. 204— tuberculatus, Kiener — tuber- 

 culosus, Quoy — tumidulus, Beeve — nivosus. Reeve. — Testa 

 ovato-elongata, aut ovata, imperforata, solidiuscula, viridula 

 aut lutescens, castaneo plus minusve tincta et punctata ; 

 anfractus subangidati, liris numerosis seriatim plus minusve 

 squamatis vel spinosis cingulati ; apertura ovata aut sub- 

 circularis, fauce argentea. Operculum subcirculare, crassum, 

 extus elevatum, granulosum, ad peripheriam albo-coerules- 

 cens, medio pallide rufescens. — A very variable species. 

 F. 17 represents the typical form; f. 18, Quoy's tuhercidosus 

 {tuberculatus, Kiener); f. 77, Keeve's tumidulus; f. 32, 

 Reeve's nivosus ; f. 63 represents a comparatively smooth 

 variety with an acute spire, and two brown and white articu- 

 lated ribs at the base next the columella, which I had almost 

 described as a distinct species ; but after carefully comparing 

 it with other and intermediate forms I have decided to 

 include it. — Hab. Nicobar Islands, Mauritius, Ceylon, South 

 Sea, New Caledonia, &c, 



16. AEGYEOSTOMus, pi. ii. f. 10 and 12, Linnccus, Sjst. 

 Nat. (12th edit.), p. 1236, 624 — var. margaritaceus, Linn., 

 f. 12 — argenteus, Chemnitz — princeps, Philippi — La- 

 marc kii, Philippi — carduus, Fischer. — Testa ovato-turbinata, 

 lutescente-alba, aut viridis, fusco plus minusve maculata 

 et radiata; anfractus convexi, concentrice striati, costis 

 numei'osis validis, interdum conspicue squamatis cingulati ; 

 apertura ovata, inferne product a, fauce sulcata aroentea ; 

 labrum plicatum ; columella leviter arcuata, ad basin in- 

 terdum effusa. Operculum extus valde convexum, virescens 

 aut pallide castaneum, granulosum. — An extremely variable 

 opecies ranging from the frondose shell described by 



