680 PLIOCENE MOLLUSCA. 



Natica Beyrichi, von Koenen. Plate LVI, fig. 12. 



1882. Natica Beyrichi, von Koenen, Norddeutsch. Miociin., vol. ii, p. 223, pi. v, figs. 1, 2. 3b. 



1883. Natica millepunctata, Nyst (non Linne), in Dewalque. Prodrome, p. 422. 



1886. Natica (Nacca ) Beyrichi, Dollfus et Dautzenberg, Feuille des Jeunes Natur., vol. xvi, p. 141. 

 1893—98. Natica Beyrichii, A. Bell, Proc. Boy. Irish Acad. [3], vol. ii, p. 628, 1893 ; Trans. Roy. 

 Geol. Soc. Cornwall, vol. xii, p. 145, 1898. 



Specific Characters. — Shell strong and solid, obliquely ovate; whorls 4, 

 convex, the last much the largest, nine-tenths the total length ; spire small, very 

 short, with a pointed apex; suture slight; month large, semilunar, expanded, 

 angnlate above, rounded below ; outer lip forming nearly a right angle with the 

 body-whorl; umbilicus large, deep; umbilical ridge very small and narrow; inner 

 lip with a thick callus. 



Dimensions. — L. 22 — 34 mm. B. 22 — 32 mm. 



Distribution. — Not known living. 

 Fossil: St. Erth. 



Miocene : North Germany, Belgium, Touraine. 



Pliocene : Albenga, Fango-nero near Siena. 



Remarks. — This species is reported from the Miocene of North Germany, 

 Belgium and Touraine, and from the Pliocene of Albenga and of the neighbourhood 

 of Siena by von Koenen, who also identifies it in part with the N. millepunctata of 

 Nyst from the Bolderien of Antwerp. It belongs to the millepunctata group, but 

 the umbilical ridge is much finer than in the type of that species. Von Koenen 

 says some of his North German fossils attain a height of 34 mm. Our specimen, 

 which is from St. Erth, measures 22 mm. 



Var. Goodmani, Etheridge and Bell, MS. Plate LVI, figs. 13, IS. 



1882. Natica Beyrichi (pt.), von Koenen, Norddeutsch. Miociin., vol. ii, p. 223, pi. v. fig. 3 a. 



1883. Natica millepunctata (pt.), Nyst (non Linne), in Dewalque, Prodrome, p. 422. 



i 

 I arietal Characters. — Resembles A. Beyrichi, but is much smaller and the spire 

 is flatter ; umbilical ridge nearly obsolete. 



Dimensions. — L. 10 — 15 mm. B. 8 — 15 mm. 

 Distribution. — Not known living. 



Fossil : Miocene : Antwerp. 

 Remarks. — The specimens here figured are from the Warburton Collection of 

 St. Erth fossils at the British Museum, where they bear the MS. name of Natica 

 Goodmani, Etheridge and Bell. They seem to me to agree with one of those 

 described by von Koenen as N. Beyrichi (op. cit.), of which they may be regarded, 

 perhaps, as a dwarf variety. I retain the name given by the authors above 

 quoted, but as varietal. 



