1849.] SHARPE ON THE SECONDARY ROCKS OF PORTUGAL. 181 



Fig. 3 h. Section of the same specimen. 

 Fig. 4. Upper valve of another specimen. 



Cardium corrugatum, n. s. Pl. XIV. fig. 3. 



Nearly orbicular ; covered with coarse irregular concentric wrinkles, 

 except down the posterior edge, which has a few longitudinal irregular 

 ribs. 



Length 3 inches ; breadth 2 J inches ; thickness 2 inches. 



Found in the lowest beds of the hippurite limestone between Lou- 

 res and Bucellas, and in subcretaceous limestone at Fontanellas, a little 

 north of Cintra. 



Distinguished from C. Hillanum and all the species of that group 

 by its coarse, irregularly wrinkled surface : the longitudinal ribs are 

 confined to a very small portion of the shell, in which it resembles 

 C. dissimiley Sow. and C. impressum, D'Orb. 



Cardium Olisiponense, n. s. Pl. XIV. fig. 4 « & 4 6. 



Shell oval, very gibbose, inequilateral ; covered with very nume- 

 rous regular, fine, equal ribs radiating from the beak to the margin, 

 which are separated by rounded interstices twice as wide as the ribs. 

 Probably furnished also at each side with a few longitudinal rows of 

 spines 1 Beaks produced and distant. 



Length 2^ inches ; breadth If- inch ; thickness ]|- inch. 



Very abundant in the upper beds of the hippurite limestone at 

 Lisbon. 



The specimens of this shell found at Lisbon are all casts on which 

 the ribbing is strongly marked ; they show some traces of the bases 

 of lateral spines. In form and marking it resembles the C. Mouto- 

 nianum, D'Orb., Cardita tuhercidata. Sow., from which it is distin- 

 guished by the regular equality of its ribbing, and by the ribs show- 

 ing themselves on the interior of the valves. 



Plate XIV. fig. 4 « & 5. Views of different specimens. 



Corbula Cost^, n. s. Pl. XX. fig. 2. 



Transversely subovate ; slightly inequivalve, the left valve larger ; 

 beaks involute, placed near the anterior end ; cardinal margin ob- 

 lique ; surface smooth, with regular, distant, slightly raised, concen- 

 tric lines. 



Length l^inch; breadth \\ inch. 



In subcretaceous limestone on the coast at San Pedro de Muriel, 

 near Meirinha Grande. 



This shell resembles C. trigona, Roemer, but is more inequilateral 

 and oblique. It is dedicated to Dr. F. A. Pereira da Costa, Professor 

 of Mineralogy and Natural History of the Polytechnic School at 

 Lisbon, to whose kindness I owe the specimen figured. 



Corbula Edwardt, n. s. Pl. XXI. fig. 2 «. & 2 6. 



Transversely oblong, very inequivalve ; truncated anteriorly, much 

 produced posteriorly. Beaks very unequal, near the anterior end. 

 Hinge-line straight, extending to the posterior extremity. 



vol. VI. — part I. o 



