290 - WORMS. TESTACEA. 68. Mytiius. 



Born. Muf. Caf. Vind. teft. p. 121. <vign. fig. A. 



Chemn. conch. 8. tab. 80/%. 717.-— 721. a, b. 



Inhabirs American and Indian Seas ; about 8 inches long and" 

 fomething broader; the infide is beautifully polifhed and 

 produces the true Mother of pearl, and frequently the moft 

 valuable pearls; the outlide fometimes fea-green or chefnuc 

 ' or bloom-colour with white rays, or whitifh with green rays ; 

 wheji the outer coat is removed it has the fame perlaceoua 

 luftre as the iniide : tne younger ihells have ears as long as 

 the fhell and refemble fcallops. 



Unguis. Shell roundifh longitudinally ftriate pellucid and (lightly 

 eared. 

 Inhabits the Mediterranean. Muf Lud. Ulr. 539. ». 131. 

 Shell very thin hyaline, with very" fine perpendicular ftria?, 

 about the fize of a man's nail: is probably of th$ genus 

 ©ftrea. 



C. Ventricofe or convex. 



* Litho- Shell cylindrical, rounded at both ends. 

 phagus, Barbut. tab. \o.fiig. 5. Rumpf. Muf. tab. 46. F. 



Argen<v. Conch, tab. 26. K Zoom. tab. 7 .fig, 5. 



John/l ex/ang. tab. 15. fig. 18, 19. 



Bonan. recr. Z.fitg. 27 — 29 ? Muf. Kirch. 2.fig\ 27, 28. 



Tains, amb. aq. tab. 9 .fig. 13. 



Lifter conch, tab. 427. tab. 437, the laft: figure. 



Gualt. test. tab. 90, D. Lefjer test. fig. 132. 



Born. Muf. Caf. Vind. ted. tab. J. fig. 4.* 



Chemn. conch. 8. tab. 82. fig. 729, 730. 

 2. Cinnamon colour. Chemn. 8. tab. 82. fig. 730. 75/ ju"*^> 



Inhabits European American and Indian Seas, penetrating and 

 eating away corals rocks and even the harden* marbles : about 

 an inch broad and 3 long ; marked with arched tranfverfe 

 ilriae; fhell black bay or greenifh, within opal-blue filvery- 

 white or perlaceous, The European fpecimens have a thin 

 brittle fhell ; the Indian ones are fofter and nearly coriaceous. 



•Jtugofus. Shell rhombic oval brittle rugged antiquated and rounded 

 at the ends.. 



Pennant Brit. Zool. iv. tab. 63. fig. 72. 



Schrcct. Eir.l. in coneh. y. tab. q.fig. 14. a, b. 



inhabits Northern European Seas and lakes ; and is ufually found 

 lodged in great numbers in lime Hone, each in a feparate 

 apartment, with apertures 5 - too fmall for the fhell to pafs through 

 without breaking the ftone ; fhell about the fize of the laft joint 

 of the little finger, dirty grey, within half blue half white, 

 and marked with very (mall longitudinal ftrise crofling the tranf- 

 verfe wrinkles. 



Bitot 



