MALACOZOA. TROPIOI'GDA. LAMELLIBRANCHIATA. 273 



thin with twenty -six little elevated, convex, glossy ribs, which 

 toward the margins are marked with transverse lamellae, be- 

 coming elevated on the anterior end, and still more so on the 

 posterior, where they sometimes resemble flattened spines ; 

 the colom* white, with irregnlar bands or spots of red, more es- 

 pecially at the posterior end ; the inside white, the margins 

 plicato-crenate. Length four-twelfths and a-half, height four- 

 twelfths. 



Not very uncommon off the sandy coast; sometimes brought 

 up by the lines : Aberdeen, Peterhead, and Gamrie. 



Cavdium fasciatum. Mont. Test. Brit. Suppl. 30. PI. 27. f. 6.— 

 Cardium fasciatum. Turt. Brit. Biv. 189. — Cardium fasciatum. 

 Flera. Brit. Auim. 422 — Cardium fasciatum. Penu. Brit Zool. j 

 Ed. 2. iv. 191. 



4. Cardium exiguum. Diminutive CocMe. 



Shell subcordate, suborbicular, somewhat oblique, convex ; 

 wdth the dorsal margin longer than the anterior, which is 

 rounded, the posterior end obliquely subtruncate ; the valves 

 thin, with twenty-four little elevated, convex, smoothish ribs, 

 which, toward the anterior end, are marked with transverse 

 lamellee, and at the posterior with prominent tubercles ; the 

 grooves between the ribs very narrow, toward either end of the 

 shell, but especially at the anterior, transversely striate or 

 marked with minute compressed papilla) ; the colour white, 

 sometimes with reddish markings ; the inside white, often red- 

 dish or brownish near the posterior end ; the margins plicato- 

 crenate. Length about four-twelfths of an inch, height some- 

 what less. 



Not very uncommon off the sandy coast ; found at Aberdeen 

 first by Mr, Davidson, and afterwards by Miss Anne Macgil- 

 livray. 



Cardium exiguum. Grael. Syst. Nat. 32o5. — Cardium exiguum. 

 Mont. Test. Brit. 82.— Cardium exiguum. Turt. Brit. Biv. 187.— 

 Cardium exiguum. Flem. Brit. Anim. 422. 



5. Cardium Icevigdtum. Smooth Coclde. 



Shell roundish-oval, much produced behind, moderately 

 convex, covered with a yellowish-brown or greenish-grey epi- 

 dermis ; the valves rather thin, marked with very munerous 

 obsolete ribs, the interstices between which are faintly striated 

 longitudinally ; the colour beneath the epidermis reddish- 

 white ; the inside glossy white ; the margin crenato-sulcate. 

 Length two inches, height two inches and a-half. 



