62 



have been brought to this country by Mr. Cuming from 

 Mindoro and Calapan, Philippines. Atlantic Ocean^ Lam. 



50. P. Rastellum. (pi. xiii. f. 30.) Lam. Anim. s. Vert, 

 vi. p. 166. 



T. rotundata^ compressa ; auriculis magnis, radiatim striatis, 

 marginibus erecto-squamatis ; costis novem, gradatim decli- 

 nentibus, tribus medianis rotundatis, squamis minutis ; late- 

 ralibus angulatis^ squamis rectis, acutis ; 'colore aurantiaco, 

 costarum interstitiis angulatim fusco-maculatis, lateribus 

 maculatis ; vel albo^ fusco maculate. Long. 1. 40. ; lat. 0. 40. ; 

 alt. 1.25.; polL 



A compressed, nearly equilateral species, with the auricles 

 large, radiately striated, marginated at the base, with erect 

 sharp scales on the edges. Ribs 9, gradually shelving down, 

 the three centre ones rather large and rounded, with small 

 triangular scales on the top ; the lateral ones rather smaller 

 and angulated; the scales on the extreme ones sharp and erect. 

 This species is distinguished from P. squamatus, (figured in 

 Reeve's "Conchologia Systematica" as P. Rastellum, Lam.) in 

 being regular, and smooth, having the sides of the ribs 

 undefined, aud the scales small in proportion. Our authority 

 for the identity of this species is that of Delessert, who has 

 figured several varieties in his work on the Lamarckian species. 

 Mr. Norris's collection. " Habite les Mers du Nord," Lam. 



51. P. PiCTUS. (pi. 20. f. 233.) nob. 



T. oblique ovata, compressa ; auriculis sub-eequalibus, mar- 

 gine serrato, radiatim sulcatis, ad basin emarginatis ; lateribus 

 striatis; costis 13, triangulatis, elevatis, Icevibus ; interstitiis 

 angustis, bi-sulcatis, crenatis : colore pallide fulvo, fasciis et 

 punctis et lineis rubris variegato ; intus albo ; Long, 0. 80. ; 

 lat. 0. 25. ; alt. 0. 85.; poll. 



Obliquely oval, flat, ears nearly equal, with the edge of that 

 in the under valve, serrated ; radiately striated, emarginated 

 at the base ; at each side of the shell there is a small space 

 slightly striated ; ribs 13, square at top, with slanting sides ; 

 interstices narrow, defined by two small grooves, and crenu- 

 lated; colour, dull white, with broad irregular bands, fine 

 transverse lines, and spots of variegated red. Isle of Baicus. 

 Mr. Cuming. 



52. P. suPERBUS. (pi. xii. f. 11.) nob. 



T. sub-ovali, obliqua, postice expansa, compressa, crassa ; 

 auriculis parvis, obtusis; costis 23, crassis, rotundatis, laevibus, 

 interstitiis angustis ; colore prope umbones roseo, prope mar- 

 gines, pallide luteo,fasciis rubris, pra5ruptis,angulatis variegato. 

 Long. 2. 40; lat. 0. 65. ; alt. 2. 60. ; poll. 



