90 



limbo lato, nigro. Long. 1| ; alt. § ; lat. y^ poll. Hab. Feejee 

 Islands. 



In the early stages the color is grass green, then passing 

 through dark purple to coal black. It is remarkable for the per- 

 fect flatness of one valve. Its destitution of hinge teeth brings 

 it in Lamarck's genus Meleagrina. 



Avicula nigra. Testa mutica, inequivalvis, ecaudata, eden- 

 tula, fusca, antrorsum lobata ; valva dextra convexiuscula, pos- 

 tice integer, antice profunde emarginata ; auricula triangulari, 

 crenulata. : valva sinistra convexior, postice profunde emargin- 

 ata : margarita ex argenteo coerulescens ; limbo lato, fusco. 

 Alt. 2; long. If; lat. ^ poll. Dredged at Singapore. 



More like A. margaritifera in form than any other, but is less 

 retuse, destitute of scales, and having its substance a plain pur- 

 plish black. It belongs to the section Meleagrina. 



Avicula mactjlata. Testa solidula, ventricosa, per-inequi- 

 lateralis, oblique rotundata, ecaudata ; margine caudali parum 

 producto ; extus calcarea, nigro radiata : auricula triangularis, cre- 

 nulata ; fissura profunda : margarita pallide aurea ; limbo cal- 

 careo lato, vitreo, albo et nigro radiato : margo cardinalis latus, 

 incrassatus ; dente cardinali papilliformi ; dente laterali brevi, 

 postice incrassato et deflecto, in valva dextra bifurcato ; cicatrice 

 musculari reniformi, profundo. Long. If ; alt. If ; lat. ■§ poll. 

 Hab. Tutuilla, Samoa Islands. 



The peculiar magnesian external coating, radiated with dark 

 purple, the golden nacre, and the porcelain-like marbled limbus, 

 make this a strongly marked species. 



Avicula fucata. T. saccata, retrorsum obliqua, per-inequi- 

 valvis, scabra, rosaceo et flavido radiatim picta : auricula pra3- 

 grandis, elongata ; fissura byssali profunda : valva dextra con- 

 vexiuscula ; angulo postico acuto : valva sinistra ventricosa, 

 antice integra, acutangularis, plica magna munita : cardo denti- 

 bus conspicuis : margarita argentea, violacescens ; limbo corti- 

 cali cretaceo, croceo et rosaceo radiato. Long. 2 ; alt. 2£ ; 

 lat. ■§■• Hab. Feejee Islands. ? 



A small species, colored much like A. margaritifera ; but the 

 wing curves in the opposite direction, and it is provided with a 



