70 SUPPLEMENT TO GREAT OOLITE MOLLUSCA. 



Corubrash of Scarborough, in which rock it is rare. The lower grit of the upper portion 

 of the Inferior Oolite at Rodborough Hill, near Stroud, has produced a considerable 

 number of specimens, for the most part smaller, and sometimes more nearly equilateral ; it 

 also occurs in the same position at Leckhampton Hill ; at each of these Inferior Oolite 

 localities it is associated with a larger, more lengthened, aud more depressed species. 

 (C. complanata, Lye.). Corbis depressa, Desh., from the Oxfordian strata of Viel, 

 St. Remy, approaches nearly to it in the general outline, but is more depressed and some- 

 what less ovate. 



CORBICELLA suBANGULATA, Lye. Tab. XL, fig. 9. 



Testa ovata sub-compressa, transversa, umbonibus antemedianis , mcdiocri magnitudine, 

 margine cardinali oblique declivi, later e postico angulo oblique instructo, maryine antico 

 subconcavo, sitperficie plicis incrementi maynis irregularibus. 



Shell ovate, somewhat depressed, transverse ; umbones of moderate size, placed anterior 

 to the middle of the valves ; hinge-border of moderate length, sloping obliquely down- 

 wards ; the posterior side has an oblique angle ; the anterior border is slightly concave ; 

 the surface has numerous plications of growth, which become large and irregular towards 

 the lower border. 



Allied to C. complanata, Lye., from which it is distinguished by the strongly marked 

 posterior angle, and by the larger umbones ; our specimen is imperfect, at the posterior 

 extremity. 



Geological Position and Locality. The Forest Marble of Laycock ; in the collection 

 of W. Walton, Esq. 



CYPRINA ISLIPENSIS, Lye. Tab. XXXV, fig. 13. 



Testa ova/o- transversa, convexa, Iffvi, obliqua, umbonibus antemedianis magnis, 

 incurvis, lunula magna, excavata, area parva lanceolata ; latere postico compresso, angulo 

 olliquo formante ; basi elliptica curvata; striis concentricis tenuibus, irregularibus, 

 subobsoletis. 



Shell ovately transverse, convex, smooth, oblique ; umbones large, incurved, placed 

 anterior to the middle of the valves ; area small, lanceolate ; posterior side compressed and 

 slightly concave, forming an oblique and well-defined angle with the other portion of the 

 surface ; lower border curved elliptically, forming an angle at its junction with the posterior 

 border. Nearly allied to Cyprina Loweana, Mor. and Lye., from which it is distinguished 

 by the larger umbones ; larger lunule, by the posterior flattened or concave area, and by 

 the well-defined oblique and acute angle, which renders the posterior extremity some- 

 what rostrated. 



