548 MM. Foord and Crick — On Nautilus elegans, Shy. 



sutures are bent backwards in a broad sinus on the sides of the 

 shell, and are nearly straight on the periphery. Siphuncle about 

 its own diameter below the centre. Ornaments of the test (type- 

 specimen) consisting of regular, transverse, prominent ribs (flattened 

 in casts), separated by interspaces about half the width of the ribs, 

 occasionally bifurcating; about seven of the ribs are contained in 

 the space of an inch; they are curved sigmoidally on the sides of 

 the shell, and form a deep sinus upon the periphery. 



Fig. 1. 



Nautilus elegans. — a, lateral view of a cast, showing the sutures and ribbing ; the 

 umbilicus is partly filled with the matrix ; b, front view, showing the position of 

 the siphuncle. Drawn from Sowerby's type-specimen (No. 5671) contained in 

 the British Museum. A little more than one-third natural size. 



Remarks. — English specimens of this species are usually in a 

 compressed and distorted condition ; but there is a specimen in the 

 British Museum Collection (No. C. 37), which is quite uncompressed 

 and shows the characters of the species admirably — sutures, 

 siphuncle, etc. The largest specimen we have seen measures 

 about one foot in its greatest diameter, and in its greatest breadth 

 about 6^ inches. 



Affinities and Differences. — Nautilus elegans is allied to JV. pseudo- 

 elegans, d'Orb., but differs from it in having a much more compressed 

 form and finer ribbing. N. Atlas, Whiteaves, is a more inflated 

 shell, and has the siphuncle near the periphery. iV. elegantoid.es, 

 d'Orb., differs from N. elegans in the more quadrate section of its 

 whorls, in having the siphuncle nearer the inner (dorsal) margin 

 and the ribs straighter on the sides of the shell and more frequently 

 subdivided. 



Horizon and Locality. — Lower Chalk. Folkestone, Kent ; Eingmer 

 and Lewes, Sussex ; Ventnor, Isle of Wight ; Cliffe Anstey, Wilt- 

 shire. 



