532 PLIOCENE MOLLUSCA. 



1890—91. Scalaria frondicula, de Bourj, Boll. Soc. Malac. Ital., vol. xiv, p. 297, no. 72, 1890; 



Linctoscala fro7idicula, vol. xv, p. 194, pi. iv, fig. 4, 1891. 

 1896. Scalaria frondicula, Bernays, Bull. Soc. Beige Grc'ol., vol. x (Memoires), p. 129. 

 1907. Scalaria frondicula, Eavn, Danske Kgl. vid. Selsk. Skrift. [7], vol. iii, p. 295, pi. iii, fig. 14. 

 1912. Scalaria frondicula, Tescli, Med. v. d. Eijks. v. DelfstofEeu, No. 4, p. 70, no. 159. 

 1912. Scala (Spiniscala) frondicula, Cossmanii, Ess. Pak'oconcli. compar., vol. ix, p. 30, pi. i, 



figs. 28, 29. 

 1914. Scala (Spiniscala) frondicula, Cerulli-Irelli, Palaeont. Ital., vol. xx, p. 221, yA. xx, figs. 21, 



22, 26. 



Specific Characters. — A species variable both in form and in tlie number of its 

 costa3, not unlike S. frond osa, but having a narrower base and a more elongate spire; 

 the whorls are convex and slightly disjoined, the spinous termination of the ribs 

 being less marked and prominent than in that shell ; the suture is deep and, as in 

 S. fi'ondosa, a basal ridge is wanting. 



Dimensions. — L. 20 mm. B. 8 mm. 



Distrilmtion. — Fossil : Coralline Crag : Gedgrave, Sutton, Boyton, Waltonian : 

 Little Oakley. Newbournian : AYaldringfield. 



Miocene : Belgium, Denmark. 



Lower Pliocene : Biot, northern Italy (very common), Tuscany. 



Upper Pliocene — Casterlien (zone (i Isocardia cor) : Antwerp. 



Scaldisien : Belgium, Holland. Italy — Asti, Bologna, Monte Mario. Sicily — 

 Caltabiano, Messina. 



.Remarks. — 8. frondicula is common in the Coralline Crag of Sutton and 

 Gedgrave, occurring also, though rarely, in the Waltonian and Newbournian zones 

 of the Red Crag. It seems to be widely diffused in the Italian Pliocene, specimens 

 from which are regarded by M. Cossmann as the typical form of this species. 

 Sign. Cerulli-Irelli figures several varieties of it from Monte Mario, but their costse 

 are not so numerous as in the Crag fossils. 



A nearly allied form from the Mediterranean under the present name has been 

 identified by Jeffreys and the Marchese di Monterosato with our Crag shell, but 

 M. de Boury doubted whether they are the same. 



He considered, moreover, that the Mediterranean form of S. frondicida differs 

 from Wood's species, proposing to call it S. frondiculoides. 



Sub-genus LAMELLISCALA, de Boury, 1910. 

 Scala (Lamelliscala) frondosa (J. Sowerby). Plate XLVIIT, figs. 21, 22. 



1829. Scalar ia frondosa, J. Sowerbj, Min. Concli., vol. vi, p. 149, pi. dlxxvii, fig. 1. 



1842-48. Scalaria frondosa, S. V. Wood, Ann. Mag. Nat. Hist. [1], vol. ix, p. 535, 1842; Mon. 



Crag Moll., pt. i, p. 92, pi. viii, fig. 15, 1848. 

 1871. Scalaria frondosa, Nyst, Ann. Soc. malac. Belg., vol. vi, p. 108, no. 119. 

 1871-84. Scalaria sohita, Jeffreys in Prestwich, Quart. Journ. Ueol Soc, vol. xxvii, p. 145, 1871 ; 



Proc. Zool. Soc, p. 136, 1884. 



