110 INVERTEBRATA. 



Pinna Robin aldina, d'Orbigny. 



(?) Pinna gracilis, Phillips, 1828. Geol. Yorkshire, pi. 2, f. 22. 

 P. rugosa, Roemer (non Schl.) 1839. Ool. Geb. Swp. p. 32, pi. 



18, f. 1 — 3. 

 P. Robinaldina, d'Orb., Terr. Grit. HI. p. 251, pi. 330, f. 



1—3. 

 it Pictet and Renevier, Pal. Suisse, Terr. Apt. 



p. 117, pi. 16, f. 5. 



Localities. Brickhill (Woodw. Mus., and in Mr J. F. Walker's 

 Cabinet), Atherfield, Speeton (?). 

 N. Europe. Hildesheim (Gottingen Museum). 

 S. Europe. Perte du Rhone (Mid. Neocomian). 



Plicatula Carteroni, d'Orbigny. 

 (Plate v., fig. 4, a, b.) 



Plicatula Carteroniana, d'Orb., 1846. Pal. Fr., Terr. Cret. in. 



p. 180, pi. 462, f. 5—7. 

 M „ Pictet and Campiche, 1870. Pal. Suisse, 



Terr. Cret. St Croix, p. 265, pi. 183, 

 f. 3, 4. 



A common shell at Upware. The lower valve is usually deeper 

 than in the French specimen, and the smaller valve is rarely spinous, 

 but has 8 — 10 broad, slightly arched ribs. Specimens which have 

 been found in protected situations (as within oyster-shells) have 

 the spines on the ribs of the lower valve much produced so as to 

 form delicate curved spines -Jgth inch long. 



At Brickhill this species occurs as a small variety, with only 

 five or six (sometimes eight) strong ribs on the lower valve. 



Localities. Upware, Brickhill, Potton, Hythe (Woodw. Mus.), 

 Folkestone (Coll. Mr Meyer). 

 N. Europe. Brunswick. 



S. Europe. Mid. and Lower Neocomian, St Croix, Hau- 

 terive, Neuchatel, Bonvillers. 



