VERMETUS (PETALOCONCHA) [NTORTUS. t57 



Specific Characters. — Shell turreted, strong and solid ; whorls but slightly convex, 

 excavated and somewhat concave above ; ornamented by two sharp, prominent 

 spiral ridges, the lower one just above the snture forming a keel to the whorls, the 

 other being central, and by exceedingly fine thread-like lines ; spire elongate but 

 comparatively short, regularly diminishing in size, with a blunt and twisted apex ; 

 suture slight. 



Dimensions. — L. 35 — 45 mm. B. 14 mm. 



Distribution. — Not known living. 



Fossil : Waltonian Crag : Little Oakley. 



Miocene : Denmark, Touraine, Vienna basin, Italy. 



LoAver Pliocene: Portugal (Lower Helvetian). Italy — Castellarquato. 



Upper Pliocene : Tuscany, Val d'Era. 



Remarks. — The Crag specimen figured under this name is from Oakley ; it 

 corresponds with some I obtained from the Faluns of Touraine. It is in very fresh 

 condition, nearly perfect, showing clearly the fine, characteristic spiral sculpture 

 of this species, and does not present the appearance of being derivative, but as it 

 occurs in the Upper Miocene of Denmark, and possibly in that of North Germany, 

 it may be so. On the other hand, it is found in the Upper Pliocene of Tuscany, 

 and is perhaps one of those many Miocene species that lingered on in the Anglo- 

 Belgian basin until Waltonian- Scaldisien times. Our knowledge of the Miocene 

 fauna of Belgium is unfortunately very imperfect. 



By some authorities T. bicarinata is identified with T. Archimedis, but Homes 

 considered them distinct. His figures show the latter to have a longer spire. In 

 our Crag fossil the spire is comparatively short, corresponding most nearly with 

 the shell given by Dr. Ravn under the latter name from the Upper Miocene of 

 Esbjerg. 



The sub-genus Archimediella was proposed by Prof. Sacco for a group of the 

 Turritellidse specially characterised by having two prominent spiral ridges. 



Genus VERMETUS, Adanson, 1757. 



Sub-genus PETALOCONCHA, Lea, 1845. 

 Vermetus (Petaloconcha) intortus (Lamarck). Plate XLIV, figs. 33, 34. 



1818. Serjmla intorta, Lamarck, Hist. Nat. Anirn. sans Vert., vol. v, p. 865, no. 889. 



1844. Vermetus intortus, Philippi, Enum. Moll. Sic, vol. ii, p. 144. 



1842-8. Vermetus intortus, S. V. Wood, Ann. Mag. Nat, Hist. [1], vol. ix, p. 532, 1842 ; Mon. Crag 



Moll., pt. i, p. 113, pi. xii, fig. 8 a, 1848. 

 1856. Vermetus intortus, Homes, Foss. Moll. Tert. Wien, vol. i, p. 484, pi. xlvi, fig. 16. 

 1870. Vermetus intortus, A. Bell, Journ. de Conch., vol. xviii, p. 350, no. 359. 



