58. P. Plica, (pi. 20. f. 237 to 239.) Lin. Syst. Nat. 

 p. 1145. 



T. rotuiidata, sub-trigona,ventricosa, crassa, radiatim striata, 

 prope umbones complanata ; auriculis parvis, sub-sequalibus, 

 obtusis, striatis, ad latera coarctatis : cardine plicato ; costis 

 tribus centralibus, crassis, rotundatis, et quatuor lateralibus 

 ininoribus, iiitus dentato-plicatis ; colore vario, plerumque 

 maculis magnis fasciatim variegato, cardine fusco. Long. 1. 

 40.; lat. 0. 60.; alt. 1. 30,; poll. 



Of a rounded, trigonal form, ventricose, tbick-, radiately 

 striated ; tbe auricles small, nearly equal, blunt, striated, con- 

 tracted at the sides ; hinge perpendicularly plicated ; there 

 are 3 central ribs, and 2 on each side much smaller ; the 

 colour is various, generally a light ground variegated with large 

 patches of a darker colour, the hinge nearly always brown. 



Nicobar. Ceylon. China. 



59. P. coRALLiNOiDES. (pi. xii. f. 3, 4.) D'Orb. Mollusc. 

 p. 102. Ostrsea vittata, sub-rotundata, Gmel. 



T. rotundata, ventricosa, aequivalvi, radiatim striata, postice 

 producta; auriculis sulcatis, obtusis, anticis majoribus, ad basin 

 emarginatis, cardine oblique plicato ; costis decern, crassis, 

 iatis, paralelle nodosis, intiis dentato plicatis ; colore rubro, 

 nebuloso, costis alternis pallidioribus. Long. 2. 10. ; lat. 1 ; 

 alt. 1. 90. : poll. 



A rounded shell, Avith nodular ribs. Differing from P. 

 nodosus in being much smaller when full grown, much more 

 finely striated, more ventricose, and more spread at the sides, 

 having the ribs equal, and the knobs less considerable. 



60. P. MAGNiFicus. (pi. XV. f. 114.) Sotv. Zool. Proc, p. 

 109. 1835. 



" T. sub-sequivalvi, sequilaterali, auriculis ineequalibus, striis 

 radiantibus, exiguis, numerosissimis, radiisque tredecim, 

 crassiusculis, rotundatis, nonnunquam sub-nodosis, intiis alba, 

 purpureo marginata: long. 5. 5.; lat. 2.; alt. 5. 5.; poll.'^ 



The colovir is bright red. Mr. Cuming's collection. 



East Columbia. 



61. P. suB-xoDOSus. (pi. XV. f. 97. 112.) Sow. Zool. 

 Proc. p. 109. 1835. 



" T. sul3-aBquivalvi, eequilaterali, auriculis ineequalibus, striis 

 radiantibus, numerosissimus, radiisque decem, crassis, rotun- 

 datis, alternatim nodoso-vesicularil)us vel sub-nodosis, intus 

 plerumque purpureo signata. Long. 5. 25.; lat. 2. 75.; alt. 

 5, ; poll. 



H 



