UNICARDIUM. 10:3 



Unicardium vectense, sp. nov. Plate. XXV, figs. 8—11. 



BcscripHon. — Shell thin, much inflated, oval or slightly subquadratc, inequi- 

 lateral, the anterior part rather larger than the posterior part; length a little 

 greater than height. Antero-dorsal margin short, nearly straight. Anterior 

 margin rounded, making an obtuse angle with the antero-dorsal margin, and 

 curving rapidly to join the moderately convex ventral margin. Posterior margin 

 rounded, slightly truncated. Postero-dorsal margin slightly convex. Umbones 

 prominent, contiguous, cur^ang inward and forwainl. Ornamentation consists of 

 numerous, strong, somewhat irregular, concentric ribs. Ligament in a long, 

 narrow groove. Teeth absent or poorly developed. 



Measurements : 



(1) (2) (;5) (4) 



Length . 20 . 18 . 10 . 12 mm. 



Height . 19 . 17 . 15 11-2 „ 



(1 — 4) Crackers, Atlierfiekl. 



Affinities. — The shell is relatively higher, the umbones more prominent, and 

 the rilis rather stronger than in F. Ebra/ji, de Loriol.^ 



Distnbntion. — Lower Greensand: Crackers of Atherfield, Perna-hed of Sandown, 

 and Ferruginous Sands of Shanklin. 



TJnicardium, sp. Plate XXV, fig. 12. 



A specimen of rnicardiitm Ironi the LTpper Greensand of South Devon- was 

 collected by Sir H. T. De la Beche and is now in tlie Museum of the Geological 

 Society, No. 1580. It resembles U. vectense, but the umbones are not so promi- 

 nent and the ribs are .smaller, more numerous, and more regular. 



Uxii\\i;nirM ? oauitixim {Pii'td and Rovx), 1852. 



1852. CoRBLS GAULTiNA, F. J. Piclct anil W. Rout. Moll. Foss. Gris verts ilc 



Geneve, p. 448, pi. xxxiv, fif;. 4. 

 1866. Fimbria — F. J. Pidet and G. Campiche. Foss. Terr. Crct. Ste. 



Croix (Mater. Pal. Suisse, ser. 4), 

 p. 282, pi. cxxii, figs. 3, 4. 

 1871. — — F. Sfolirzl-a. Pala?out. Indica, Cret. Fauna S. Iiulia, 



vol. iii, p. 2.52. 

 1875. CoRBis — A. J. Jidcs-Broicne. Quart. Jourii. Geol. Sec., vol. xxxi. 



p. 300. pi. XV, fig. 9. 



1 ' Gault de Cosnc' (1882), p. 70, pi. viii, figs. 13-16. 

 - Probablv from near Siilinontli or Bluckdciwii. 



