486 LDIN^ID.E. 



as to give the appearance of a double suture. Tlie surface is ex- 

 ceedingly smooth, no revolving lines being detected l)y the magni- 

 fier. The base of the aperture is somewhat narrowed, and pro- 

 longed downwards, and considerably effuse. The twisted fold of 

 the columella is less conspicuous than in P. hetcrostropha. The 

 shell becomes more ponderous and yellowish by age ; and the red- 

 dish rib along the outer lip, and the enamel on the columella, much 

 thicker. 



Oeiius BULI]\US, Adansox. 1757. 



Fig. 737. Tentacles filiform, setaceous. Mantle simple-edged, 

 and not reflexed over the shell. Foot long, acuminate 

 behind. 



Shell sinistrorsal, elongated, polished, thin ; spire acu- 

 minated ; aperture narrow, produced anteriorly ; inner lip 

 simple ; outer lip acute. 



B^'dols°J. Jaw (of B. kyprioruni) strongly arched, narrow, carti- 

 laginous, brown. 



tus. 



Bidinus differs from Plnjsa in having a simple, nnfringed mantle. 

 The shell is also more slender and more liighly polished. It is less 

 common in North America than Phi/sa, but usually appears of a 

 large size. BuUrms priiiceps, Phillips of Central America, and some 

 of the South American species, are remarkably well developed. 



Adanson's name Bulinus has priority over Aplexa, Fleming, and 

 Nmita, Leach, and is accompanied by a careful description and ex- 

 cellent figure. 



Bulinus elongatus. 



Fig. 143. 



Shell thin, slender, elongated, apex acnto, pale yellowish ; whorls six, polished ; 

 suture slightly impressed ; aperture half as long as the shell. 



Physa hi/pnonim, Hai.deman, Mod. 36, pi. 5, figs. 4-9 (1842). — Adams, Shells of Ver- 

 mont, 154 (1842). 



Phi/sn elom/ata, Sav, ,Jonrn. Acad. Nat. Sc. ii. 171 (1821) ; Binnhy's ed. 68. — Gould, 

 Inv. 214, fi<?. 143 (1841). — De Kay, N. Y. Moll. 81, pi. 6, fig. 346 (1843). — Anon. 

 Can. Nat. ii. 211, fig. (1857). 



Ph,/f;n i/liihra, T)E Kay, N. Y. Moll. 80, pi. 5, fig. 83 (1843). 



Pl,i/m plominfimi, Lewis, Bost. Pr. v. 122, 298 (1855). 



Phtjsn Inrrita, J. de C. Sowb. Fauna Bor.-Am. iii. 315. 



ApJc'Xii hjiiwornm, CiiEMT, Man. de Concli. ii 481, fig. 3556. 



Bulinus liijpiwrum, W. G. Binnev, Smith. Inst. L. and Fr. W. Sh. ii. 99, fig. 170 (1865). 



