SOME TERTIARY FOSSILS FROM THE MIIKE COAL-FIELD. 11 



between the ridges is concave, while the surface above the 

 upper one gently ascends to the suture. The whole surface 

 seems to have been ornamented with fine spiral lines. 

 Found at a depth of 405 feet. 



10. Aturia ziczac (>^ow.). 

 PI. III. Figs, lab, 8ab. 



Aturia zie-zac Edwards. A Monograph of the Eocene Molhisca, part I, 

 Cephalopoda, p. 53, pi. IX, figs, la — b. 



Nautilus zic-zac Deshayes. Deser. Coq. Foss. Env. Paris, vol. II, p. 765, 

 pi. 100, figs. 2, 3. So\Yerby. Mineral Conchology, vol. I, p. 9, pi. I, fig. 3. 



Edwards in his Eocene Mollusca, " describes this species as 

 follows:"— 



Shell ventricose, smooth ; umbilicus closed ; septa concave ; 

 lateral lohes narrow, jJointed ; dorsal lobes much curved ; siphimcle 

 large, continuous, trump et-shajjed. 



There are two specimens belonging to this characteristic 

 species of the older Tertiary. The one is a fragment of a large 

 whorl ; the other, though smaller, is more complete and 

 measures some 63 millim. in diameter, while its thickness is 

 about 20 millim. in its thickest part, so that the specimens 

 belong to the so-called compressed variety of Edwards. The 

 narrow pointed lateral lobes are clearly seen in both specimens, 

 as they are not furnished with shells. 



The species is found in Europe in the Eocene and Miocene 

 formations, and in Egypt in the Kurkur Series which is as- 

 signed to the Palœocene. 



The depth at which the Miike shells were found was 613 

 feet. 



