GIBBULA. 203 



Var. BARBARA Moiits. PL 33, figs. 84. 



Spire elevated, conical, acuminate ; suture but feebly canaliculate ; 

 .shell thinner and umbilicus narrower than in typical G. ardens. 



Gulj of Gales. 



G. UMBiLicARis Linne. PI. 32, figs. 63, 64, Qo. 



Shell umbilicate, conical, cinereous, reddish, or purplish-brown, 

 obscurely clouded, dotted or flamed with white; spire conical, 

 acuminate; whorls about 7, slightly convex, spirally striate or 

 Urate, microscopically obliquely striate ; the lirse generally subobso- 

 lete on the last whorl ; periphery obtusely angulate ; aperture 

 rather small, oblique, rounded-quadrate, angled at the base, smooth 

 within ; columella arcuate above, straightened below. 



Alt. 12-16, diam. 14-20 mill. 



Mediterranean Sea. 



T. lurbiVwaris Linn., Sxjst. Nat, xii, p. 1229 (1766).— Lam., An. 

 s. Vert., vii, p. 28.— Fischer, Coq. Viv., p. 143, t. 45, f. 2.— Buq., 

 Dautz. et Dollfus, 3foU. du Rouss., p 376, t. 45, f. 1-8. — T.fns- 

 catus Gmel., Syst. Nat., xiii, p. 3576. — Deshayes, Exped. Morce, p. 

 142. — Gibbula mediterraitea Risso, Hist. Nat. I'Enr. Mcrid., iv, p. 

 136. — G. desserea Risso, loc. clt., p. 136. — T. roissyi Blainville, 

 Faune franc, p. 282, t. lOa, f. 9. — T. zonatus Jeffreys, Piedm. 

 Coast, p. 28.-7'. umbilicaris var. latior et patula (Monterosato) 

 Bug., Dautz. et Dollfus, Moll. Mar. du Rouss., p. 378, t. 45, 

 f. 6, 7, 8. 



A species very closely related to G. ardens v. Salis. It differs in 

 the smoother, more angulated body-whorl ; the less canaliculate 

 sutures ; rounder mouth ; deeper umbilicus, which, although as broad 

 (or nearly so) as in G. ardens, is much less funnel-shaped, but nearly 

 of the same width to a considerable depth ; the Avhorl is also more 

 angulated around the umbilicus than in the other species, and the 

 columella is not dentate. 



The coloration is extremely varialjle, as in nearly all the Mediter- 

 ranean Trochids. In fact nearly every species of the smaller 

 Trochidae of this province exhibits the same patterns and modifica- 

 tions in coloration, commencing with (1) a series of white flames 

 beneath the sutures, which (2) are continued as longitudinal, oblique, 

 or undulating stripes to the base, or (3) are broken into maculations 

 or articulations over the Avhole surface, or (4) the entire surface is 

 either creamy white or uniform dark. 



