15 



greatest near the aperture. They are narrowest at the nm])ilicns, and 

 widen n-raduall}- towards tlie periphery, where they measure about two 

 lines in widtli. 



Greatest diameter, iibout seven inches; ;i})proximate width of ajierture, 

 (whieli coincides with the maximum thickness at a right angle to the 

 diameter) slightly over tive inches ; height of aperture, in the centre, 

 three inches and seven Hues. The specimen being very much distorted, 

 these measurements must be received with caution. 



One of the most striking specimens in Mr. Richardson's collection is 

 the large Nautilus described above. Unfortunately this unique example 

 is badl}' preserved, and veiy much crushed out of shape. The siphuncle 

 is not visible anj'where, although the fossil happens to be broken in two 

 pieces, in such a way as to expose most of the interior. The distortion is 

 greatest in the chambered part of the shell, so that it is impossible to tell 

 how many septa there were to a volution, or to detine their exact shape. 



The s])ecies is very nearly related to the Nautilus eleyans of D'Orbign}-, 

 and to the N. pseudo-eleyans of the same author ; but it may prove to be 

 distinct from I)oth. 



It is clear that the Queen Charlotte Island fossil is not the Nautilus 

 elegans of Sowerby, for in that shell the aperture is said to be " obtusel}' 

 sagittate, with the posterior angles truncate." The desci-iption and figures 

 in the "Mineral Conchology" give one the idea of an obliquely com- 

 pressed shell, with an aperture whose height is much greater than its 

 width. Before the writer was aware that Pictet had shown tliat the 

 Nautilus elegans of D'Orbigny and Sharpe is distinct from the N. elegans of 

 Sowerb}', the same conclusion had been arrived at after a careful stud}' 

 of the original diagnoses. D'Orbigny describes his N. elegans and N 

 pseudo-elegans as follows. Italics being substituted for Roman letters to 

 emphasize certain points: — 



Nautilus elegans, D'Orbigny (as of Sowerby). 

 " N. testa globulosd inflatd, transversim sulcata ; sulcis incurvis, 

 reflexis, umbilico impresso, non perforata ; apertura lata, semilunari ; 

 septis siraplicibus, arcuatis; siphunculo ad tertiani exteriorem septorum 

 partem perforato." 



Nautilus pseudo-elegans, D'Orbigny. 



N. testa discoided, inflatd; transversim undulato-sulcata, subumbilicatd ; 

 apertura semilunari; septis arcuatis, in umbilico sinuosis ; siphunculo 

 non centrali ad inferiorum limbem septorum adplicato." 



