VENUS. 24 \ 



them. In the second plate of the eighth vol. of the Linnean 

 Transactions, these two are placed together, exhibiting their 

 different appearances. 



Western coasts : very rare. v. m. 



21. Venus orhiculata. Orbicular Fenus. 

 Montagu, pi. 29. f. 7- 



Shell orbicular, rather flat, white, striate longitudinally 

 and transversely j inside white, with the margin plain : 

 beaks extremely small, with a minute heart-shaped depres- 

 sion under them : hinge with two teeth placed together, 

 and a remote one standing transversely ; the margin where 

 the lateral tooth is placed projecting into an angle : diame- 

 ter five-eighths of an inch. 



It has much the appearance of the last, but is not so flat, 

 is more rounded and more coarsely reticulate, and the la- 

 teral tooth is much more remote. 



Found by Captain Laskey, nearDunbar : very rare. 



22. Venus undata. Waved Femis. Fig. 54. 

 Pennant, pi. 58. f. 3 Donovan, pi. 121 Llun. Trans. 



vi. pi. 17. f. 17, IS. 



- Shell very thin and transparent, rather convex, yellow- 

 ish white with mostly a ferruginous tinge, marked with 

 fine irregular transverse striae or wrinkles, a little irregu- 

 larly undulate round the circumference ; inside glossy yel- 

 lowish-white, with the margin very sharp edged and plain : 

 beaks prominent, rather pointed, very little inclining to one 

 side, without the heart-shaped depression under them : 

 hinge with three teeth in one valve, and two in the other : 

 length above an inch ; breadth rather more. 

 Western coasts, and Dublin bay. v. v. 



23. Venus exoleta. Antiquated Venus. 

 -Lwter,.pl..291. f. 127, and pi. 293. f. 129 Pennant, 



pi. 5/. f. 3~D Costa, pi. 12. f. 5 Donovan, pi. 42. f. 1 

 -Dorset Cat. pi. 8. f. 5 Linn. Trans, vi. pi. 17- f. 9,- 10, and 

 viii. pi. 3. f. 1. 



Shell strong, orbicular, flattish, often a little angular to- 

 wards the front margin on the cartilage side, with extremely 

 hue and regular close-set transverse striae, and a few deeper 

 Y antiquated 



