Cardium. 
MOLLUSCA. CARDIADJS. 
42S 
440. C. IcBvigatum . — Shell subovate, the ribs obscure and 
obliterated anteally ; covered with a brownish-olive glossy cu- 
ticle. 
Pectunculus subfuscus. List. Conch, t. cccxxxii — C. Isev. Linn. Syst. i. 
1123. Penn. Brit. Zool. iv. 91. t. lii. f. 40. Mont. Test. Brit. 80. 
Turt. Biv. Brit. 190 — An inhabitant of deep water, on various parts 
of the coast. 
Diameter about two inches ; slightly truncated retrally, and produced at 
the anal angle ; ribs faint, depressed ; crossed by unequal furrows andstrise ; 
the shell, when young, is more produced, and of a uniformly greenish-yellow. 
441. C. serraUim. — Shell ovate, lengthened, glossy, and ap- 
parently smooth. 
Pectunculus Isevis, Test. Conch, t. ccxlix — C. ver. Linn. Syst. i. 1123. 
Turt. Biv. Brit. 192. t. xiii. f. 5. — West of England and Pentland 
Frith. 
Length about an inch and a half, breadth a quarter less, white or yellow- 
ish, tinged with pink or orange retrally ; the longitudinal strije are minute, 
the margin crenulated on the ventral, and serrated on the oral edge. 
442. C. edentulum. — Subovate, a single oblique tooth at 
the hinge, with a lateral plate on each side. 
Mactra radiata, Don. Brit. Shells, t. clxi. — C. ed. Mont. Test. Brit. 
Sup. 29 — Found by Mr Laskey on Langston beach, near Portsmouth, 
after a severe storm in 1800. 
EXTINCT SPECIES. 
1. C. Hillanum . — Shell nearly circular, a little oblique, with numerous 
concentric striae, retral edge straightish, longitudinally furrowed. — Sower. 
Min. Conch, t. xiv. upper fig . — Green Sand. 
2. C. Plumstedianum — Subcordate, smooth, retral part longitudinally fur- 
rowed. — Souier. Min. Conch, t. xiv. middle fig — Plastic Clay. 
3. C. nitens — Boundish, hind end rather shouldered ; smooth, shining ; 
marked all over with faintish longitudinal punctated lines, which are rather 
more distinct at the retral side. — Sower. Min. Conch, t. xiv. lower fig. — Lon.- 
don Clay. 
4. C. Parkinsoni. — Gibbose, rather oblique, posterior side straightish ; sur- 
face slightly rugose, with nearly forty longitudinal ribs, having slight trans- 
verse risings on each. — Sower. Min. Conch, t. xlix — In Crag. 
5. C. Hibernicum . — ^Very broad and deep ; retrally truncated, concave, with 
a central eminence ; anteally elongated, beaks incurved, small ; striated lon- 
gitudinally, the intervening spaces or ribs flat, Avith obsolete transverse 
scales. — Sower. Min. Conch, t. Ixxxii. f. 1, 2, and t. nlii. f. 3. — In Grey Wacke 
Limestone. 
6. C. alwforme Triangular, ventricose, longitudinally ribbed ; retral side 
truncated, produced, near the hinge ; concentrically ribbed ; anteally pro- 
duced, much compressed, ribbed — Sower. Min. Conch, t. nlii. f. 2. — -Carhonife* 
rous Limestone. 
7. C. proboscideum. — Suborbicular, gibbous ; retral side straight, about 
twenty longitudinal rows of large caiialiculated spines, with two rows of 
lesser ones between ea.ch. — Sower. Min. Conch, t. clvi. f. 1. — In Green Sand. 
