192 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [NoV. 21, 



The interior lias not been seen. 



Plate XXVI. fig. 2 « & 5. Two views of the same specimen. 



Terebratula Beirensis, n. s. Pl, XXVI. fig. 3 a &; 3 b. 



Shell nearly quadrangular, with rounded sides ; ornamented with 

 about thirty-two obtuse and slightly elevated ribs, eight of which are 

 raised up near the anterior margin in the mesial fold ; dorsal valve 

 flat posteriorly, with a deep sinus anteriorly ; ventral valve very con- 

 vex, and produced at the anterior margin in an elevated fold, which, 

 as well as the corresponding sinus on the dorsal valve, only com- 

 mences at the middle of the shell ; sides depressed and smooth near 

 the hinge, somewhat dilated anteriorly ; beak incurved. 



Length and breadth 1 inch ; height ^ iuch. 



From the Jurassic limestone below the coal at Cape Mondego. 



This shell is more nearly related to T. vespertilio, Brocchi, of the 

 cretaceous system, than to any other described Terebratula : it diifers 

 from that species in having the front more produced than the sides, 

 the beak much incurved, only about half as many ribs, and other 

 minor points. Among the Jurassic species it is nearest to T. tetra- 

 hedra, Sow., from which its dilated sides and obtuse flattened ribs 

 separate it widely. Only one specimen has been seen. 



Plate XXVI. fig. 3 a k h. Two views of the same specimen. 



Natica Lusitanica, n. s. Pl. XXIV. fig. 5 a, 5h, &; 5 c. 



Shell subglobose, with a slightly produced spire of three volutions ; 

 marked mth faint lines of growth, otherwise nearly smooth. Mouth 

 broadly lunate. Columella solid. 



Length \ of an inch ; diameter \ of an inch. 



From limestone of the subcretaceous period, three miles south-west 

 of Alenquer. 



Plate XXIV. fig. 5 a. Natural size. 



Fig. 5 5 & 5 c. Magnified. 



Nerita turbinata, n. s. Pl. XXIV. fig. Q a 8c Q b. 



Semi-globose ; spire small, partly immersed ; whorls slightly flat- 

 tened above, tumid in the middle, and a little produced at the base, 

 crossed by numerous strongly marked lines of growth. 



Length \ of an inch. 



Found in limestone of the subcretaceous series, three miles south- 

 west of Alenquer. 



This elegant little shell somewhat resembles N. cost at a, Min. Con. 

 460. f. 5 & 6, but has not the strong costee of that species : the pro- 

 duced columella, which has been partly broken in the only specimen 

 found, gives it a somewhat turbinated form. 



Plate XXIV. fig. 6 a. Natural size. 



Fig. 6 b. Magnified. 



Neritina bicornis, n. s. Pl. XXIV. fig. 7. 



Semi-oval, slightly and regularly convex, with the margins pro- 

 duced into two nearly equal pointed ears ; spire produced and slightly 



