67 



Interstices smooth. Ground colour pale yellowish, ohscurely 

 mottled with smoky brown. Bureas, Philippines. Mr. Cuming. 



65. P. Pes-felis. (pi. xvii. f. 162. pi. xx. f. 234.) Lin. 

 Syst. Nat. p. 1146. Bornii, Pay/: O. corallina, Poll. 



T. ovali-subtrigona, compressa, scabra, radiatim sulcata, 

 eequivalvi, sub-eequilaterali, crassa; auriculis ineequalibus, 

 nodoso-sulcatis : posticis parvis, anticis magnis : costis 8, 

 crassis, latis, elevatis, sulcatis. Interstitiis latioribus, sulcatis. 

 Colore, fusco-rubescente, fasciis nigris, et maculis albis varie- 

 gato; variat purpureo. Long. 2. 50.; lat. 0. 72.; alt. 2. 90.; poll. 



A well known species from the Mediterranean and also 

 from the Persian Gulf. 



68. P. parvus, (pi. xx. f. 227-8.) G. B. Sowerby, Sen. 

 Zool. Proc. 1835. p. 110. 



T. subovata, depressiuscula, sub-eequivalvi, eequilaterali, 

 albicante : auriculis insequalibus, graniferis : valvis radiatim 

 costatis; costis 8, ina;qualibus, transversim striatis: interstitiis 

 radiatim sulcatis et transversim striatis: Long. 0. 75.; lat. 

 0. 25. ; alt. 0. 80.; poll. 



"Found in coral sand on the reefs." Lord Hood's Island. 

 Mr. Cuming. 



67. P. imbricatus. (pi. xiii. f. 32-3.) Gmel. p. 3318. 

 No. 12. sauciatus Gmel. Chem. t. 69. f. h. 



T. sub-trigona, complanata, sub-kevi, sub-eequivalvi : auri- 

 culis inaequalibus, complanatis, ad marginem nodosis : posticis 

 parvis, obtusis : anticis magnis, acutis : valva sinistra com- 

 planata : costis 9, rotundato sub-angulatis, tuberculatis, forni- 

 citis, globosis ftrantibus: alternis depressis : valva dextra, 

 sub-ventricosa, costis noduliferis a^qualibus 10. Colore albo, 

 roseo-maculato, costis alternis rubro maculatis, intus ad mar- 

 ginem purpureo, medio luteo ; nonnunquam occurrit purpureo 

 immaculato. Long. 1. 35.; lat. tuberculis exclusis 0. 40; 

 alt. 1. 55 ; poll. 



This flat trigonal species is remarkable for the hollow 

 imbricated tubercles which are placed at nearly equal distances 

 on 9 alternating ribs. I believe that the figure in Chemnitz 

 referred to by Gmelim for P. sauciatus is only a variety of 

 this species in the state most common in collections, having 

 the knobs worn down. Red Sea. 



68. P. rubromaculatus. (pi. xiii. f. 34.) nob. 



T. ovali-subtrigona, ajquivalvi, sub-cequilaterali, sub-com- 

 pressa : auriculis imequalibus, scabroso-sulcatis : posticis 

 parvis ; anticis magnis, costis 18, prope marginem squamosis, 

 alternis depressis, minoribus, interstitiis keviter striatis : costis 



