84 PEOCEEDINGS OF THE GEOLOGICAL SOCIETY. [DcC. 6, 



Locality and Position. — Sutton and Southerndown series at Dun- 

 raven &c. Common. 



From the imperfect state of my specimens, I am unable to say 

 whether the interspaces between the ribs are punctated. 



This shell is distinguished from L. punctata by its straight ante- 

 rior side ; the size of the ribs brings it nearest in character to 

 Lima Valoniensis, Def., cited by Dumortier (Depots Jnrassiques du 

 Bassin du Ehone, p. 54) as occurring associated with Pecten Valo- 

 niensis, Def. In form it bears much resemblance to L. eocaltata, 

 Terquem, from the Infralias of the province of Luxembourg; but 

 the ribs are a little wider than in that species. In the absence, 

 therefore, of the characters of the whole shell I cannot identify it 

 with either of these species. 



11. Lima, sp. 



I have the hinge-area of a remarkable Lima which bears a great 

 resemblance to the hinge of Lima cometes, Dumortier, ' Bassin du 

 Rhone,' pi. xxiii. figs. 1 and 2 ; but in the absence of the rib-charac- 

 ters I cannot identify it, as by its form it is also allied to L. tuber- 

 culosa (Terquem). The hinge-line is not straight, but forms an 

 obtuse angle with the ears ; the ears are strongly plicated. 'No lunule. 

 The shell is very thick around the ligamental pit, but is abruptly 

 hollowed out below. 



12. OsTREA L^vis, spec. nov. PL III. fig. 2. 



Shell extremely convex, elongate, and ovate. Surface with con- 

 centric, somewhat irregular, fine, imbricated folds of growth or deli- 

 cate wavy lamellae. Margin thick and entire. Length l|inch; 

 breadth |-rds of length. 



Locality and position. — Sutton series at Sutton and Langan. Com- 

 mon. 



This shell varies in different localities, being sometimes very nar- 

 row ; it is readily distinguished from Ost. Uassica by its convexity, 

 and does not occur in such numbers together as that species. 



13. OsTREA MULTICOSTATA, Muust. PL III. fig. 1. 



Shell elliptical, frequently nearly equilateral, thick. IJmbo near 

 the hinge, from which strongly elevated straight or slightly wavy- 

 ribs diverge ; ribs acutely rounded, crossed by fine concentric lines 

 of growth, equally visible in the interspaces ; interspaces the same 

 size as the ribs. Eibs extend to the margin, causing it to be undu- 

 lated ; margin thick, rounded. Length 3 inches ; breadth ^ths of 

 length. 



Locality and position. — Sutton and Southerndown series at Sutton 

 &c. Common and characteristic species. 



The area of attachment is devoid of ribs and frequently occupies a 

 large portion of the shell. 



This shell is variable, affecting at different times the appearance 

 of 0. spondyloides, 0. multicostata, and 0. difformis. Terquem, in de- 

 scribing the Ostrece of the Province of Luxembourg, proposed to unite 



