358 VERMETIDiE. 



Adanson ; the species are inhabitants of tropical seas, 

 but at present are but imperfectly known. 



Species of Vermetus. 



annulus, Rouss. quadrangulus, PJiil. 



bicarinatus, Desk. radicula, Stimj). 



Hindsii, Gray. spiratus, Phil. 



lumbricalis, Linn. tenuis, Rouss. 



Novae Hollandiae, Rouss. tulipa, Rouss. 

 Panamensis, Rouss. 



Genus BIVONIA, Gray. 



Operculum rudimentary, small, ? spiral. 



Shell tubular, irregularly twisted, usually adhering in 

 masses ; ajjerture round, peritreme acute, continuous. 



Si/n. Vermicularia, b, Schtim. 



Ex. B. glomerata, Bivona, pi. 39, fig. 1. Operculum, 

 B. glomerata, fig. \,o, 1, h. Shell, B. glomerata, fig. 1, c. 



The operculum is red, convex in the middle, with a 

 thin, flat margin, and a central muscular scar; the shells 

 resemble Serpula-, are irregularly twisted and entwined 

 together in masses, often of considerable size ; there are 

 several species, inhabiting the Mediterranean. 



Species of Bivonia. 



decvissata, Gmel. subcancellata, Phil. 



glomerata, Bivon. triquetra, Phil. 



semisurrecta, Phil. 



