Lamarck's Genera of Shells-. 251 



9th Family. 



ScALARiANA. (3 Genera.) 



No plaits on the columella ; margins of the aperture circu- 

 larly united. All sea shells. 



The shells of the Scalariana have a tendency to form a loose 

 spire, so that the whorls are often disunited, and do not rest 

 one on another. 



1. Vermetus *. 



Shell thin, tubular, loose spiral; spire adhering by the apex. 

 Aperture orbicular, margins united. Operculum cartilaginous. 



This shell has great resemblance to a serpula ; its animal, 

 however, is not one of the annulata, but a true molluscum, and 

 properly placed with the trachelipoda. (See Adanson's Senegal, 

 PI. xi. fig. 1. Vermetus.) The vermeti are commonly found in 

 groups, twisted together. 



One Species. Vermetus lumbricalis t. 



Shell attached by the apex of the spire, extended anteriorly 

 into an ascending tube, thin, transparent, reddish yellow. 

 Senegal. PI. VIII. Fig. 161. 



2. SCALARIAt. 



Shell sub-turrited, spire more or less elongated, last whorl 

 rather larger than the penultimate ; ribs longitudinal, elevated, 

 interrupted, sub-acute. Aperture nearly round; margins cir- 

 cularly united, and terminated by a thin curved varix. 



Type. Scalaria pretiosa §. (Turbo scalaris, Linn.) 



Shell conical, umbilicated, loose, spiral, pale yellow ; ribs 

 white ; whorls disunited, smooth, the last ventricose, Indian 

 Seas. PI. VIII. Fig. 162.— 7 recent species, and 3 fossil. 

 3. Delphinula ||. 



Shell subdiscoidal, or conical, umbilicated, solid, internally 

 pearly, whorls of the spire rough, or angular. Aperture entire, 

 round, sometimes triangular ; margins united, generally fringed 

 or varicose. 



Distinguished from turbo, by the united margins. 



* From vermin, a norm. i From lumhricux, «n earth-worm. 



t Vromscala, aliight of steps. 4 Costly, •precious. 



II Dim. from delphinus, a dolphin. 



