I5B Mr, William Wood's Ob/ervations on the 



margantlfera, Linn, S)Jl. Nat. ed, Gmel. i. p, 3219. Penn. Br. Zoot 

 No. 18. /. 43. / 18. Da Coft. C'jnch, t. 15./ 15. 

 Lift, Cmch, t. 149./ 4. — An Ang. App. 15. /. i. 



f, I. Chemn, Cmch. 6. /. I. /• 5. GW/. left. t. 102. 



y! C. Klein, Oftr. t, 10. y^ 47, Knorr, Vergn, 4. /. 25. 



/ 2. 



Tab. XIV. Fig. 5, 6. 



The hinge of this fhell is very thick and rugged ; the 

 tooth in the upper valve blunt, and uneven at the 

 top. Om one fide there is a fulcus, which receives a 

 fmall tooth from the oppofitc valve, at the fame 

 time that the large one fits into a correfponding 

 depreffion. 



This, with the following fhell, completes Da Coda's 

 genus of My a. The two former he has placed 

 among the Chama. 



piSlorum^ Linn, Syjl. Nat, ed. Gmel, 3218. Penn. Br. Zoo/. No. 17. 



t, 4^.jr. 17. Da Coft. Br, Conch, p. 228. /. 15. /. 4. 4. 

 ^—Elem, Conch, t. 7» jf, 12. Lift, Conch, t, i^J.f. 2, 3. 

 — An. Ang, t, 1. f, 30. App, t. I. f, 4. Chemn, 

 Conch, 6. /. \. f, 6. Argenv, Conch, t, zy, f, 10. — 

 Zoom, t, 8. y! II. 



Tab. XIV. Fig. 7, 8. 



In the hinge of the M. pidiorum we meet with an 

 arrangement of teeth different from any other of 

 the Britiih fpecics of this genus. 



Near the beak are fituarcd two upright teeth, one in 

 each valve. The larireft of the two is ferrated. — 

 There are likewife three remote teeth, two in one 



fhell. 



