ratliately striated or nearly smooth, with the auricles ver}' 

 unequal ; the posterior being very smooth. The colouring is 

 various, most commonly consisting of large spots of purple and 

 M'hite upon a ground of light purple or yellow. Great Britain. 



82. P. HASTATUS. (pi. XX. f. 236.) nob. 



T. ovali subtrigona, subelongata, scabra; auriculis in- 

 a?qualibus, posticis minimis, anticis magnis, scabroso-sulcatis : 

 valva sinistra, costis 8, insequalilDus, valde elevatis, angulatis ; 

 spinas numerosas, erectas, subcrispatas ferentibus. costis 

 interstitialibus numerosis, ineequalilius, serratis : valva dextra, 

 costis 22, angulatis, spinosis; colore rubro, intus albo. Long. 

 0, 95.; lat. 0. 30.; alt. 1, 15.; poll. 



Oval, inclining to triangular, rather elongated, rough ; with 

 very unequal ears, the posterior ones being very small ; the 

 upper valve has eight unequal, elevated, angular ribs, with 

 numerous erect, slightly curved, sharp spines, and several 

 smaller spinose ribs in the interstices. The lower valve has 

 22 more nearly equal ribs with more nvimerous and smaller 

 spines on the angles. The only specimen we have seen 

 is in the collection of the Rev. F. J. Stainforth. 



83. P. prsio. (pi. xiv. f. G2, 3, 4, 5,) Liyi. Syst. Nat. 

 p. 1146: palliolum Chem. 



T. ovali, subasquivalvi, inaequilaterali, subirregulari, radi- 

 atim scabroso-sulcata, sulcis in valva dextra, duplicatis : 

 auriculis inaequali1)us,posticis minimus, anticis magnis, ad basin 

 emarginatis, scabroso-sulcatis ; colore vario, plerumque 

 variegata. Long. 0. SO. ; lat. 0. 95. ; alt. 1. ; poll. 



The above name has been erroneously applied to the ir- 

 regular attached shell properly called Hinnites sinuosus. 

 Tlie shells are somewhat similar in their young state. This 

 species has numerous small rough ribs which are doubled in 

 the lower valve. Mediterranean. 



84. P. ORXATTS. (pi. xiv. f. 77j 78^ 89.) Lam. Anim. 

 sans Vert. vi. p. 1 76. 



T. ovali sul)trigona, compressa, eequivalvi, scabra: auri- 

 culis incequalibus, posticis minimis, anticis magnis, acutis, 

 sulcatis ; costis valvse sinistrce numerosis infequalil)us, alter- 

 natim majoribas-valvee dextrse, duplicatis. Interstitiis scabris; 

 colore pallidissime fulvo, maculis elongatis, undulatis, fas- 

 ciatim variegato, plerumque costis tribus, albis ; occurrit 

 etiam, rubro, prope umbones solum niaculato. Long. 0. 93. ; 

 lat. 0.30.; alt. 1. 10.; poll. 



Oval, nearly triangular, rather flat, equivalve ; auricles 

 unequal, the posterior extremely small : the ribs of the upper 



