the Caribcean Islands. 543 



Testa subaequivalvis, complanata, lamellosa, irregularis, mar- 

 gine ventrali tenuissimo. Cardo linearis, verticalis, (quiescentis) 

 hians ; sulcis plurimis transversis, parallelis, oppositis, liga- 

 mentum multipartitum inter se recipientibus. Sinus byssi late- 

 ralis, subhians, infra cardinis basin, parietibus incrassatis. Im- 

 pressio muscularis unions, partitus, subcentralis. 



Perna Ephippium. Lam, 



Per. sordide flavescens, abdomine ochraceo : pallii tentaculis 

 brunneis, brevibus ; capitis tentaculis parvulis : bysso maximo, 

 longissimo, nigro-viridi, fills apice liberis. 



Testa varia, pallida, purpureo rufo vel ferrugineo picta, intus 

 medio margaritacea : margine inferno acutissimo, tenero : vertice 

 lato, recto, multisulcato, subtus cavernoso. 



Obs, Listeri figura rudis : forte species plurimae sub hoc 

 titulo confusae latent. 



Habitat gregatim frequentissima in lacubus maritimis Indise 

 Occidentalis ; edulis, pretiosa : radicibus emersis vel testis se- 

 nescentibus affixa. 



This species, so highly esteemed by the West Indian epicure, 

 has been confounded by the vulgar with the true Mangrove 

 oyster, with which it is often found. It swarms in Mustique 

 and others of the Antilles which possess salt water Lagoons, 

 hanging by the byssus in clusters to one another and to the roots 

 of various trees which Providence has with infinite wisdom at- 

 tached to sand for the protection of lands exposed to the inroads 

 of the sea, where the greater part of the vegetable kingdom 

 would inevitably perish. The Mangrove (Rhizophora Mangle) 

 is the principal supporter of the Fernce. The cylindrical clus- 

 tered roots of this marvellous tree flourish in the surf itself, and 

 the negro has only to take his basket and his hatchet to the 

 Lagoon and by cutting off a few roots to procure an abundant 

 meal. 



They arc observed to be larger and finer at certain seasons of 

 the year. The shell both in colour and outline is subject to 

 infinite variety. Some specimens are pale and unmarked, while 



