846 
XAUTILOIDEA. 
Conchology,’ and also the specimen figured in Dixon’s ‘ Geology of 
kSussex.’ The latter was figured also by Edwards in his ‘ Eocene 
Mollusca.’ One of the specimens from Hampstead (Xo. C. 606) was 
presented by II. Maitland, Esq., and one from Sheppey (No. 8970.'^) 
by Miss Wilson. 
Aturia Charles worthi^ Foord. 
1837. Xautiliis ziczac, Charleswortb, Mag. Xat. Hist, new series, vol. i. 
p. 533, f. 66 (woodcut). 
1848. Xatdihis ziczac, Mantell, ‘ Wondei-s of Geolog}*,’ 6th ed. vol. i. 
p. 247, woodcut 40, ff. 1,2. 
1849. Aturia ziczac, variety /3, Edwards, Mon. of the Eocene Molluscs, 
pt. i. Cephalopoda (Mon. Pal. See.), ]>. 55. 
Sp. Char. Shell (? young) compressed; sides very fiat, peri- 
phery very narrowly rounded ; umltilicus closed. Septa very 
approximate; thirteen in a complete whorl. Sutiiies resembling 
those of A. ziczac, but much closer together. Dody-chamber un- 
known. 
llemarks. This species was differentiated by Edwards from the 
“ true Naut. ziczac, figured in ‘ Mineral Conchology ’ ” (which he 
designated the “ first variety ” of Aturia ziczac), and placed by him 
in a second variety, (3 — the distinguishing characters of the latter 
being that “ the shell is more compressed, almost discoidal ; and 
consequently it is narrower on the ventral aspect ; the dorsal lobe.s 
are not so broad, and the aperture is of a more elongated oval form.” 
Although there is only one example of the present si)ecies in the 
British Museum, the type specimen (Xo. 68918), its characters are 
so clearly distinct from those of Aturia ziczac that it seems justi- 
fiable to separate it from that species. In its compressed form 
A. Charlesworthi agrees closely with the Dax shells (Aturia Atari ), as 
remarked by Edwards ; but on comparing it with small specimens of 
A. Atari from Turin, I find that the septa are much more numerous 
in the English species, and the shell in the latter is more compressed 
even than that of any of the continental specimens of A. Atari. 
The present species has been, admirably figured by Charlesworth and 
Edwards. The figure given by the first of these authors is con- 
siderably enlarged, that of Edwards is of the natural size. 
Horizon. London Clay (Lower Eocene). 
Localitij. Primrose Hill, London. 
Kepresented in the Collection by the type specimen, first described 
by Charlesworth, and originally contained in Mr. Wethercll’s Col- 
lection. 
